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Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 6 Climatic Regions offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 6 Question Answer – Climatic Regions

Textbook Page no. 60.

See some characteristics of the Meditrranean clifinate is just opposite to Monsoon climate of our ountry. Cimpare the climate of two tyges.
Monsoon climate
1. Influenced by Monsoon wind
2. Summer hot and humid
3. Winter dry and cool
4. Rain fall occur due to wet Monsoon wiad
5. Monsoon wind blows seasonally.

Mediterranean Climate

1. Influenced by Trade wind.
2. Summer hot and cloudless.
3. Winter wet and ful of moisture.
4. Rainfall occur due to wet westerlies wind.
5. Seasonally Trade and Westerlies blows.

Textbook Page no. 64.

Question 1.
Write your own explanation ………………….. specific climatic regions.
Answer:
cause-effect relationship of physical and scio-economic environment.
Equatorial Climatic Region :
Heavy rainfall occurs through out the year for excessive temperature. For this reason evergreen forest has grown here. The inhabitants practise shifting cultivation. They also earn money through some industries, they are not so economically developed.

Monsoon climatic Reģion :
Four types of climates found here. Heavy rainfall occurs due to monsoon wind. Deciduous and cactus typed plants are grown here. Besides lion and tiger clephant, Rhino, wolf, bear are common animals of this region. The region is industrially developed for agriculture, densely populated and economically developed.

Mediterranean Climatic Region :
Almost 16 countries belong to this climatic region. For the temperature climate evergreen and deciduous plants grow here. This region is developed in agriculture, fruit based industry and export business. Film industry has been flourished. Economically prosperous region.

Tundra Climatic Region :
Extremely cold climate through out the year. The ice melts in summer. Short cool summer. Long cold winter. Mass, lichens grow. Rarely populated region. The main livelihood is hunting. Besides, exporting importing are other occupation. Presently, the region is gradually developing.
In your opinion, which climate. opinion and cite reasons.
Effect of Climate
Reason for development
Namc of the climatic region
In Miditerranean climatic region for the influence of modrate climate the summer is dry and the winter is wet. Snowfall is rare.

Reason for Backword
Name of the climatic region
In equatorial region hot summer is experienced through out the year and annual temperatures is less. Rainfall abundant.

Other reason
Economically developed. Agriculture and fruit based industries are the main livelihood of the people.
Unhealthy climate, dense forest, poisonous insects, malaria. black fever etc. are the hindrance of the development.

Class 8 Geography Chapter 6 Question Answer West Bengal Board – Climatic Regions

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
In equatorial region the-
i) days one longer nights are shorter
ii) days are shorter nights are longer
iii) days and nights are almost equal
Answer:
iii) days and nights are almost equal

Question 2.
In equateral region nights are called –
i) Tropical summer
ii) Tropical winter
iii) Tropical autumn
Answer:
ii) Torpical winter.

Question 3.
In equaterial region in a year number of rainy days are-
i) 100-200
ii) 200-400
iii) 250-300
iv) 200-300
it Answer: 250-300

Question 4.
In equaterical region grows-
i) Brazil nut
ii) wal nut
iii) ground nut
Answer:
i) Brazil nut.

Question 5.
Brazilian rainforests in 2 sq K m can have up to-
i) 100 species of trees
ii) 200 species of trees
iii) 300 species of trees
iv) 400 species of trees
Answer:
iii) 300 species of trees

Question 6.
The inhabitants of Amazon basin are-
i) Pygmies
ii) Senuangs
iii) Red Indians
Answer:
iii) Red Indians.

Question 7.
The inhabitants of South-East Asia are-
i) Semangs
ii) Pigmies
iii) Red Indians
Answer:
i) Semangs.

Question 8.
In monsoon climatic region belongs to-
i) Amazon Basin
ii) Queensland
iii) Syria
iv) Libya
Answer:
ii) Queensland.

Question 9.
The average rainfall in monsoon climetic region is-
i) 100-200 cm
ii) 300-400 cm
iii) 150-250 cm
iv) 200-300 cm
Answer:
iv) 200-300 cm.

Question 10.
In monsoon climetic region which forest is foand-
i) mangrove forest
ii) grassland
iii) coniferous
Answer:
i) mangrove forest

Question 11.
At the coastal areas in monsoon climetic region the animal is found-
i) whale
ii) sherk
iii) Crocodile
Answer:
iii) Crocodile.

Question 12.
The main industry of monsoon region is-
i) iron and steel
ii) silk
iii) jute
iv) paper
Answer:
i) iron and steel

Question 13.
The influence of Mediterrancan climate is found in-
i) 10 countries
ii) 14 countries
iii) 15 countries
iv) 16 countries
Answer:
iv) 16 countries

Question 14.
The average rainfall in Mediterranean climetic region is –
i) 25-150 cm
ii) 100-200 cm
iii) 200-300 cm
Answer:
i) 25-150 cm.

Question 15.
The other name of Mediterranean climetic region is-
i) country of summer rainfall
ii) country of winter rainfall
iii) country of autumn rainfall
Answer:
ii) country of winter rainfall

Question 16.
The most famous fruit of Mediterranean climatic region is
i) olive
ii) mango
iii) orange
iv) straberry
Answer:
i) olive.

Question 17.
The most common cattle of Mediterranean climatic region is-
i) cow
ii) deer
iii) camel
iv) horse
Answer:
iii) camel.

Question 18.
The major industry of Mediterranean region is-
i) jute
ii) silk
iii) handloom
iv) iron
Answer:
ii) silk.

Question 19.
Italy in Mediterranean region is famous for-
i) iron
ii) mineral oil
iii) marble
iv) gold
Answer:
iii) marble.

Question 20.
Olive oil is obtained from-
i) olive
ii) grapes
iii) apple
iv) cherry
Answer:
i) olive.

Question 21.
The best film industry is developed in-
i) Rome
ii) Egypt
iii) Paris
iv) California
Answer:
iv) California.

Question 22.
Tundra region is named after-
i) Tundra tree
ii) Tundra bird
iii) one type of algae
Answer:
iii) one type of algae

Question 23.
Tundra climate is found in a very small part of-
i) northern part of Eurasia
ii) southerm part of Eurasia
iii) middle of Eurasia
Answer:
i) northern part of Eurasia

Question 24.
Virkhayansk is located at-
i) northern hemisphere
ii) equatorial region
iii) southern hemisphere
Answer:
i) Northern hemisphere.

Question 25.
In the land mass of Tundra region is found-
i) camel
ii) tiger
iii) horse
iv) sledge dog
Answer:
iv) sledge dog

Question 26.
In coastal region of Tundra region the animals found-
i) seal-whale-walrus
ii) seal-whale-crocodile
iii) seal-whale-starfish are found
Answer:
i) seai-whale-walrus

Question 27.
The inhabitants of the Northern part of Alaska is-4
i) Eskimos
ii) Fin
iii) Lapps
Answer:
i) Eskimos.

Question 28.
The inhabitants of Syberia in Eurasia is-
i) Samoyeds
ii) Eskimos
iii) Red Indians
iv) Lapps
Answer:
i) Satmoyeds.

Question 29.
In Tundra region animal is found-
i) wolf ,
ii) Polar beer
iii) Lion
iv) Tiger
Answer:
ii) Polar beer.

Question 30.
The food of the inhabitants of polar region-
i) milk and biscuits
ii) milk and strawberry
iii) milk and berry
Answer:
iii) milk and berry

Question 31.
The one of the major experting goods of Tundra region is-
i) tea
ii) tobaceo
iii) meat
iv) fleece
Answer:
iv) fleece

Question 32.
As the means of transportation in water the inhabitants of Tundra region use-
i) bajra
ii) launch
iii) kayak
Answer:
iii) kayak

Fill in the blanks : (1 mark for cach question)

1. Africa’s ______ river basin belongs to equatorial region.
2. Middle America’s Panama, ______ parts of climetic regien. islands experience equatorial
3. Through out the year worm summer exists resulting annual temperature range of only _______.
4. In equaterial region heavy ______ rainfall occurs.
5 . In the evening 3 or 4 pm the _______ louds cover the sky.
6. Equatorial climatic zone is influenced by ________ zone.
7. The tropical forest in Brasil’s Amazon river basin is called _______.
8. _____ tree is mostly found in equatorial climatic region.
9. ______ lives in the zaireh basin of equatorial region.
10. Pygmies, Red IndiAnswer:Semangs are gathering and ______ tribes.
11. Main plantation crops in equatorial clinatic region are cocoa, banana ______.
12. In equatorial region rubbar is produced in _____, Java – of Sourth-East Asia.
13. Cocoa and palm are cultivated in ______.
14. Sugarcane and ______ are cultivates in West Indies.
15. Mineral oil and are found abundantly in Sumantra, Java and
16. The Arbian word ‘Mousim’ means ______.
17. In Asia besides India monsoon climate is found in ______, _______
18. Due to ______ snowfall occurs in North-West India and some part of _____.
19. South-West monsson wind from Arabian sea and _____ causes heavy rainfall in Indian subcontinent.
20. For whimsical nature of _______ flood and droughts occur annualy.
21. Formation of depression in the Bay of Bengal causes ______ and _____.
22. In the monsoon climate dense _______ forests are found.
23. The places where the annual rainfall is more than 200 cm the forest like____ sishu garjan are grown in even dry season.
24. The places where the rainfall is 100-200 cm the forest of sal, teak, sisam ____, – mango, jackfruit are found.
25. ______ of Gir forest in Gujarat and of Sundarban is famous.
26. The landform of monsoon climate region is _______.
27. The Mediterrancan climatic region is found in – of North America.
28. ______ Libya, Algeria. Tunisia of Africa are influenced by Mediterranean climate.
29. Mediterranean climatic region is called as –
30. During summer high pressure belt is situated in the ______ region.
31. ______ is one of the main trees of Mediterranean region.
32. The main crop of Mediterranean region is _______.
34. Mediterranean region is called _______.
35. _______ and _______ are found in Italy of Mediterranean region.
36. _______ is found in Spain.
37. _______ from grapes is manufactured in France.
38. _______ of California is famous for film industry.
39. _______ of Portugal is one of a main port.
40. _______ of Australia is a fomous port.
41. _______ of America belong to Tundra region.
42. Some part of _______ in Southern hemisphere belongs to Tundra climatic region.
43. In Tundra climatic region rainfall is _____.
44. _____ and ______ flower bloom in Tundra region.
45. The people of Tundra region live in house made of ice or ______.
46. The people of Tundra region cultivate by using latest technology by ______.
47. _____ and _____ are the common phenomena of Tundra region.
48. In the northern Norway at _______ port sun remains visible at midnight.
Answer:
1. Congo
2. Coastarica, Caribbean
3. 2°C
4. Conventional
5. Cumulo-bumboo
6. Inter Tropical convergence
7. Enohona
8. Sinchona
9. Pygmies
10. hunting
11. palm
12. Malay Sumatra
13. Guinea Coast
14. Banana
15. Natural gas. Borneo
16. Season
17. Vietnam, Taiwan
18. Westerlies, Pakistan
19. Bay of Bengal
20. monsoon,
21. Thunder storm, rainfall
22. Evergreen
23. Mehogony,
24. palash, sirish, mahua
25. Lion, tiger
26. plain.
27. California
28. Egypt, Morocco
29. Country of winter rainfall
30. Mediterranean
31. Olive
32. Wheat
33. Silk
34. Basket of fruits
35. Marble and sulphur
36. Iron
37. Wine
38. Holywood
39. Lisbon
40. Adelaide
41. Canada
42. Antarctica
43. 20-30 cm.
44. Mass, Lichen
45. Igloo
46. greenhouse
47. Snowfall, snowdust
48. Hammerfest

State whether True or False : (1 mark for each question)

1. Throughout the year intence heat and heavy rainfall occur near equator.
2. In Equatorial climatic region days and nights are almost equal throughout the year.
3. Palm, cocoa and cinchona are main trees in the Selva.
4. Rubber is the main plantation crop in Malay.
5. Somalia and Madagascar are not influenced by monsoon climate.
6. North-East monsoon wind does not cause rainfall all over India.
7. Monsoon climatic region is world famous for rice cultivation.
8. Most of the roads are rough in monsoon climatic region.
9. Mild temperate climate throughout the year is the main characteristics of mediterrancan region.
10. Olive trees are seen in maximum number in mediterranean region.
11. Rome and Naoles in France are the main industrial centres.
12. Monsoon wind flows regularly throughout the year.
13. In Tundra region winters are long and severe.
14. After two months of spring summer comes in Tundra region.
15. The tundra is sparsely populated duc to adverse climate.
16. In coastal region of Tundra seal, whale, walrus are found.
17. There are 100-150 rainy days in a year in equatorial climatic region.
18. The Amazon basin was cosnected to the rest of the world by the TransAmazon Highway in 1970.
19. Monsoon climatic region is thickly populated region of the world.
20. In temperate climate region maize is the main crop.
21. Temperate climate region is rich in mineral resources.
22. Round shaped house Igloo is made of ice.
Answer:
1. true
2. true
3. false
4. true
5. false
6. true
7. true
8. false
9. true
10. true
11. false
12. false
13. true
14. false
15. true
16. true
17. false
18. true
19. true
20. false
21. false
22. true

Match the following : (1 mark for each question)

Match the column A with column B.

Column A	Column B
a) Samoyeds live	i) are evergreen trees
b) Inhabitants of Tundra climatic region	ii) is called Busket of fruits
c) Snowfall and snowstorm are common	iii) $10^{\circ}$ to $30^{\circ}$ latitudes in both hemisphere
d) Eucalyptus and rosewood	iv) trees in Congo
e) Temperate climate region	v) is thickly populated
f) Cold summer, wet winter are main	vi) in Eurasia
g) Monsoon climate region	vii) import tea, coffee, tobaceo
h) Monsoon climate is found from	viii) in Equatorial climatic region
i) Cocoa and cinchona are dominant	ix) in Tundra climatic region
j) The humidity always remains high	x) characteristies of temperate climate

Answer:
a) Samoyeds live in Eurasia.
b) Inhabitants of Tundra climatic region import tea, coffee,”tobacco.
c) Snowfall and snowstorm are common in Tundra climatic region.
d) Eucalyptus and rosewood are evergreen trees.
e) Temperate climate region is called Busket of fruits.
f) Cold summer, wet winter are main characteristics of temperate climate.
g) Monsoon climate region is thickly populated.
h) Monsoon climate is found from 10° to 30° latitudes in both hemisphere.
i) Cocoa and cinchona are dominant trees in Congo.
j) The humidity always remains high in Equatorial climatic region.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
Which region is located as equatorial region?
Answer:
The region between 5°-10° north and south latitude is located as equatorial region.

Question 2.
Which part of India belong to equatorial region?
Answer:
The south west part of India belong to equatorial region.

Question 3.
Which part of South America belong to equatorial region?
Answer:
The amazon river basin of South America belong to equatorial region.

Question 4.
Which part of Middle America belong to equatorial region?
Answer:
Middle american’s Panama. Coasterica, part of Caribbean Islands.

Question 5.
What is known as the night of the equatorial region?
Answer:
It is known as “winters of the tropies”.

Question 6.
What is known the equatorial forest?
Answer:
Equatorial forest is known as Evergreen forest.

Question 7.
Which type of rainfall occurs in equatorial region?
Answer:
Convectional rainfall.

Question 8.
What is known as the tropical forest of Brazil?
Answer:
Selva.

Question 9.
How many species of trees found in the rain-forest of Brazil in 2 sq Km area?
Answer:
300 species of trees in 2 sq Km area in Brazilian rainforest.

Question 10.
Name the inhabitant of Zaire basin.
Answer:
Pigmies live in Zaire Basin.

Question 11.
Which type of inhabitants found in upper Amazon basin?
Answer:
Red Indians.

Question 12.
Which type of people found in South-East Asia?
Answer:
Semangs are found in South-East Asia.

Question 13.
Which type of agriculture is followed in equatorial region?
Answer:
Shifting agriculture is followed in equatorial region.

Question 14.
What are cultivated in Gunea Coast of Africa?
Answer:
Cocoa and palm are cultivated in Gunea Coast of Africa.

Question 15.
When was Trans-Amazon highway constructed?
Answer:
Trans-Amazon highway was constructed in 1970.

Question 16.
What are the causes of the hinderace of economical development in equatorial region?
Answer:
Unhealthy environment, dense forest, poisonous insect, maleria etc.

Question 17.
What is the meaning of the word ‘monsoon’?
Answer:
The word monsoon means season.

Question 18.
Which region of East Africa belong to monsoon climetic region?
Answer:
Somalia, Madagascar of East Africa.

Question 19.
How many types of season found in monsoon climatic region?
Answer:
4 types of season are found in monsoon climatic region.

Question 20.
Which part of Australia experience ‘monsoon’ climate?
Answer:
Queensland Province of Australia.

Question 21.
Which countries of Asia belong to monsoon climatic region?
Answer:
India, Pakistan, Bangladesh, Srilanka, Myanmar. Thailand, Vietnam, Kamptichlia, South Chitha, Philippines etc.

Question 22.
What is the average temperature of monsoon climatic region?
Answer:
The average temperature is 25° C.

Question 23.
What is the annual rainfall of monsoon climatic region?
Answer:
Annual rainfall is 200-300 cm.

Question 24.
What is the annual rainfall of Mawsynran?
Answer:
Annual rainfall is nifore than m0re than 1200 cm.

Question 25.
Which type of vegetation found in Monsoon climatic region?
Answer:
Dense evergreen forest is found.

Question 26.
Where is the evergreen forest found in monsoon climatic region?
Answer:
Evergreen forest is found the places where the annual rainfall is 200 cm.

Question 27.
Where is mangrove forest is found in monsoon climatic region?
Answer:
The mangrove forest is found in Coastal area of monsoon climatic region.

Question 28.
Name the animals of monsoon climatic region.
Answer:
The animals are elephant, rhinocerous, cheeta, deer, wolf, monkey, fox etc.

Question 29.
Name the minerals of monsoon climatic region.
Answer:
The minerals, like coal, iron, copper, man anese, bauxite, mineral oil are found in monsoon climatic region.

Question 30.
Name the crops of monsoon climatic region.
Answer:
The main crops are rice, jute, wheat, sugarcane, cotton, oil seed, tea, coffee etc.

Question 31.
Name the fruits of monsoon climatic region.
Answer:
Fruits are mango, cherry, jackfruit, bannana, pineapple etc.

Question 32.
Name the minerals of equatorial region.
Answer:
The minerals are tin in malaya, mineral oil and natural gas in Sumarta, java and bornio.

Question 33.
What are the main industry of monsoon climatic region?
Answer:
Jute industry, cotton textile industry, tea industry etc.

Question 34.
How is the communication system in monsoon climatic region.
Answer:
The communication system is very good. The railway, roadway and airway is highly developed.

Question 35.
What are the main cities of monsoon climatic region.
Answer:
Delhi, Kolkata, Chennai, Sanghai, Dhaka, Yangoon, Bangkok etc.

Question 36.
Name a country of South America in mediterranean climatic region.
Answer:
Chilli of South America is in mediterranean climatic region

Question 37.
Name some Europian countries lie in Mediterranean climatic region.
Answer:
France, Italy, Spain, Greece, Portugal, Albenia, Yagoslava.

Question 38.
Name some Asian countries lie in Mediterrancan climetic region.
Answer:
Turkey, Israel, Syria, lebanon.

Question 39.
Name some African countries lie in Mediterranean climatic region.
Answer:
Egypt, Morocco, Libya, Algeria, Tunisia etc.

Question 40.
Name some countries of the world where Mediterranean climate is found.
Answer:
California of North America, Chile of South America, Cape Town of South Africa,
South West and South-Eastern part of Australia.

Question 41.
What are the main features of Meditiranean climate?
Answer:
Mild temperature through out the year, dry summer and wet winter.

Question 42.
What is the other name of Mediterranean climatic region?
Answer:
The other name is ‘country of winter rainfall’.

Question 43.
What are the natural vegetation of Mediterranean climatic region?
Answer:
Evergreen forest with thick leaves and hard stem.

Question 44.
Name some type of vegetation found in Meditirranean climatic region.
Answer:
Coneferous vegetation, Evergreen vegetation and shurb type vegetation.

Question 45.
Name some coniferous trees of Mediterranean climatic region.
Answer:
Pine, Fir, Cedar.

Question 46.
Name some evergreen trees of Mediterennean climatic region.
Answer:
Oak, Cork, Eucalyptus, Rosewood.

Question 47.
What are the shrub type vegetation of Mediterranean climatic region?
Answer:
Maple, Laurel, Rasemery, Lavender.

Question 48.
Name one of the main trees of Mediterranean climatic region.
Answer:
Olive.

Question 49.
Name some animals of Mediterranean climatic region.
Answer:
Donkey, Sheep, Goat, Mule.

Question 50.
Name some crops of Mediterranean climatic region.
Answer:
Maize, barley, rice, cotton, tobacco.

Question 51.
What fruits are found in Mediterranean climatic region?
Answer:
Grapes, olive, pear, apple, orange, walnut, pianult, pulm, fig etc.

Question 52.
What is the Mediterranean climatic region called for the production of fruits?
Answer:
It is called as ‘Basket of fruits’.

Question 53.
Name the minerals of Mediterranean climatic region.
Answer:
Mineral oil in California, Bankette in France, Marble in Italy, Iran \& Spain.

Question 54.
What are the different occupation of the people of Mediterranean climatic region?
Answer:
Agriculture, orchard forming and archard based,industry, trade and commerce.

Question 55.
What are the different industry of Mediterranean climatic region?
Answer:
Wine making in Italy and France and processing from olives, processing fruit products.

Question 56.
Name a special industry of Mediterranean climatic region.
Answer:
A special industry is famous film industry ‘Hollywood’ in California.

Question 57.
Name some main cities of Mediterranean climatic region.
Answer:
Los Angeles, San Francisco in California, Rome and Naples in Italy, Cape Town in south Africa, Adelaide in Australia, Lisbon in Portugal.

Question 58.
Why is Tundra region named as Tundra?
Answer:
From the name of an algae this region is named as Tundra.

Question 59.
Which countries in Europe belong to Tundra region?
Answer:
Norway, Sweeden, Finland, Narrow coast of Greenland.

Question 60.
Which countries in Asia belong to Tundra region?
Answer:
Siberia in Asia.

Question 61.
What are the climatic features of Tundra climatic region?
Answer:
Short cool summer and long severe cold winter.

Question 62.
What is the coldest place of Northern hemisphere?
Answer:
Verkhoyansk in Siberia.

Question 63.
Which place is called the ‘Land of Midnight Sun’?
Answer:
Hammerfest port in Norway.

Question 64.
What is the average temperature of Tundra region?
Answer:
Average temperature is 10° C.

Question 65.
Which type of vegetation grow in Tundra climatic region?
Answer:
Mosses, shrub type of Birch, Juniper, Alder grow here.

Question 66.
Which type of vegetation grows in the wetland of Tundra?
Answer:
Mosses, dichens, different types of colourful flowers bloom in the wetland of Tundra.

Question 67.
What animals are found in the landmass of Tundra region?
Answer:
Sledge dog, arctic fox, polar deer, caribou are found in Tundra regicn.

Question 68.
What are the animals found in the coastal region of Tundra region?
Answer:
Seal, whale, walrus and different types of fishes.

Question 69.
Name the inhabitants of Tundra region.
Answer:
Eskimos, Red Indians, Samoyeds, Yakut, Lapps etc.

Question 70.
Name the inhabitants of greenland.
Answer:
Eskimos, Red Indians.

Question 71.
Name the inhabitants of Siberia in Eurasea.
Answer:
Somoyeds, Yakuts.

Question 72.
Name the inhabitants of Finland.
Answer:
Fin.

Question 73.
What type of people live in Tundra region?
Answer:
Normodic type.

Question 74.
In which type of house the people of Tundra region live in winter?
Answer:
They live in a round shaped house called Egloo during winter.

Question 75.
Where do they live in summer when the ice is melted?
Answer:
In summer when the ice is melted they live in tent made of seal’s skin called tupics.

Question 76.
What is known as the tent?
Answer:
The tent is known as Tupics.

Question 77.
What do the people of Tundra region use for transportation?
Answer:
They use wheelles sledge and the boat Kyak made of seal’s skin for tranportation.

Question 78.
What are the garments of the people of Tundra region made up of?
Answer:
They use to skin of animals in making their clothes.

Question 79.
What do the people of Tundra region use to make weapons?
Answer:
They use bones of animals for making weapons.

Question 80.
What animals do the people of Tundra region hunt for food?
Answer:
Seal, beer, Reindeer, arctic fox and fishes from sea.

Question 81.
What are the favourite food of the people of Tundra region?
Answer:
Milk of reindeer and berry fruits.

Question 82.
Name the minerals found in Tundra region.
Answer:
Coal, iron ore, gold, mineral oil.

Question 83.
Where are gold and mineral oil found?
Answer:
Ukraine and Alaska.

Question 84.
Where is iron-ore found?
Answer:
Kiruna region.

Question 85.
Where is coal found?
Answer:
Pittsburrgh.

Question 86.
Name a railway of Tundra region.
Answer:
The railway connecting Murmansk part of Siberia to Saint Reters-burg.

Question 87.
Name a Highway of Tuntra region.
Answer:
Alaska highway.

Question 88.
What are the imported and exported good of Tundra?
Answer:
This region import tea coffee tobacco against fleece and feather of animals.

Long Questions & Answers : (3 marks for each question)

Question 1.
What is called ‘Burst of Monsoon’?
Answer:
When South-East Monsoon coming from Arabean sea branch and Bay of Bengal branch enter the Indian subcontinent and sudden and tremendous rainfall occurs. This is called Burst of Monsoon.

Question 2.
Mention the climatic characteristics of equatorial climatic region.
Answer:
The Sunrays fall perpendicular on this region through out the year. So this region experience extreme temperature. During the day temperature rises upto 38° C and at night it remain 20°-25° C. The difference between highest and lowest tange of temperature is more. Heavy rainfall occurs through out the year.

Question 3.
Write about natural vegetation of equatorial climatic region.
Answer:
In this region some or the other tree bears green leaves, flowers and fruits throughout the year. Hence, these forests are called evergreen forests. They are called Selva in the Amazon basin of brazil. Rubber, rosewood, Brazil nut, iron wood and bamboo are found in the selva. Mahogany, rubber, palm, cocoa and cinchona are the dominant trees in the Congo and Zaire basins. In southeast Asia the equatorial forests consist of ablus, sal, teak, rubber trees. In the coastal areas coconut and palm trees are common.

Question 4.
Write about animals of equatorial climatic region.
Ans.
Here birds and animals that can climb trees are dominant. Because here the forest is dense and the floor is covered with undergrowth. Monkeys, cl.impanzees, gorillas, orangutans, snakes, birds, insects and pests are found here. On land elephants, deer, rhinoceros and in water crocodiles and hippopotamus are found.

Question 5.
Write about the inhabitants of equatorial climatic region.
Answer:
Due to hot humid climate, unhygienic conditions and wild natural environment here human settlements are scanty. Equatorial climatic regions of south-east Asia are more inhabited than the Zaire ar. Amazon bisins. Main inhabitants of this region are Pygmies of Zaire basin, Red Indians of upper A mazns basin, Semangs of south-east Asia.

Question 6.
Write about farming of the inhabitants of equatorial climatic region.
Answer:
Methods of shifting cultivation are being practiced in the forest fringes to grow corns, turnip, banana, yum. After establishing colonies by Europian traders, now the inhabitants practice piantation farming. Among them rubber in Malay, Java and Sumatra of south-east Asia, sugarcane and banana in West Indies, cocoa and palm in the Guinea coast are mentionable.

Question 7.
Write about minerals and industries of equatorial climatic region.
Answer:
Minerals available in this region are – tin in Malaya, natural gas and petroleum in Sumatra, Java and Borneo. Want of raw materials has prevented the growth of heavy industries in this region. Based on local agro-based. forest-based and mineral-based raw materials some industries have emerged.

Question 8.
Mention the location of monsoon climatic region.
Answer:
Monsoon climate is found from 10°-30^{\circ \prime latitudes in both hemispheres. In Asia India, Bangladesh, Pakistan, Mayanmar, Srilanka, Vietnam, Kampuchea, Thailand, Taiwan, South China and some psrts of Philippines are under the influence of monsoon climate. Moreover, Somalia and Madagascar of East Africa, Queensland province of Australia are infuenced by monsoon climate.

Question 9.
Mention the climatic characteristics of monsoon climatic region.
Answer:
Four seasons are noticed in monsoon climate. They are – a) Winter (NovemberJanuary), b) Pre monsoon summer (March-May), c) Monsoon Rainy Season (June-September), d) Autumn (September-October). In winter North-East monsoon wind blows. It does not cause rainfall in India. But Srilanka, Coromandal coast, Andaman and Nicobar Island gets more rainfall. Average temperature of Summer is 30° C. Intense heat creates low pressure. In Monsoon rainy season water vapour in the air is maximum. Sudden and tremendous rainfall occurs. in Autumn cold weather prevails. Formation of deep depression in the Bay of Bengal causes thunderstorm and rainfall.

Question 10.
Write about settlement, agriculture, industry of monsoon climatic region.
Answer:
This region is the leading producer of rice. Besides wheat, sugarcane, cotton, oil seed and different types of fruits like mango, jumun, jack gruit, lichi, banana, pine apple are grown here. The minerals like coal, iron, copper, manganese, bauxite, mineral oil are found in this region. Jute

industry, cotton industry, tea industry, iron and steel industry are the heavy industries of this region. The communication and transport system through railways, waterways, roadways are highly developed. The popular and developed cities like Delhi. Kolkata, Mumbai are flourished in this region. Rapid economic prosperity is the feature of this region.

Question 11.
Write about location of Mediterranean climatic region.
Answer:
This climatic region lies in hot temperate zone. This type of climate is found in the Western part of the continents lie between 30°-40^{\circ latitude of both hemisphere. France. Italy, Spain, Greece, Portugal, Albania, former Yogoslavia of Europe. Turkey Israel, Syria, Lebanon of Asia; Egypt, Morocco, Libya, Algirea, Tunisia of Africa experience this type of climate. Also California of North America, Chili of South America, Capetown of South Africa, South. West and South Eastern part of Australia belong to this climatic region.

Question 12.
Write about animal rearing and agriculture of Mediterranean climatic region.
Answer:Here prevails rainless dry summer and wet winter. Hence donkey; sheep, goat, mule are reared here. Near hot deserts hen, camel are reared. This region is developed in agriculture. Wheat is the main crop. Moreover rice, maize, cotton, barley and tobacco is produced here. Due to bright and sunny weather grapes, apple, pears, olive, or ange, peach, walnut, peanuts, palm, sweeet fig and different types of citrus fruits are produced here. This region is called ‘Busket of fruits’.

Question 13.
Write about minerals and industry of Mediterranean climatic region.
Answer:
This region is not rich in mineral wealth. Mineral wealth in California, bauxite in France, marble and sulphur in Italy, iron in Spain are found here. Agriculture. orchard farming and orchard based industry, trade and commerce are main occupation here. Grapes are used in wine making in Italy and France. Oil producing from olives is a main industry in this region. Dry fruit, processed food products and flour industry is also mentionable. World famous filn industry Hollywood in California is located in this region.

Question 14.
Write about location of Tundra climatic region.
Answer:
Near the Arctic circle northern part of Canada in North America, Alaska, Northern parts of Eurasia, Norway, Sweden, Finland, coast of Greenland and Siberia in Asia are under the influence of tundra climate. This climate is also found in very small parts along the coast of Antarctica in southern hemisphere.

Question 15.
Describe about the winter climate of Tundra climatic region.
Answer:
At this region winters are long and severe cold. Winter lasts 8-9 months. At that time temperature falls 20° C-40° C. In Verkhoyansk of Siberia (coldest place of Northern hemisphere) average temperature of January remains -50.6° C. Due to severe cold entire region is covered by snow. Here snowfall and snowstorm are very common phenomena. Sun remains almost invisible in sky at that time. In continuous dark night sometimes for 2-3 hours Aurora Borealis and Aurora Australis are seen.

Question 16.
Describe about the summer climate of Tundra climatic region.
Answer:
After two weeks of spring summer comes in Tundra region. It lasts for 2-3 months. This time average temperature remains 10° C. Sunset exists for a very short duration. Though sunrays exist 22-23 hours due to slanting rays. In the northern Norway at Hammerfest port and nearer ares remain visible at midnight. For this, this region is called ‘Land of Midnight Sun’. During summer the sky remains covered by fog.

Question 17.
Describe natural vegetation and animal life of Tundra climatic region.
Answer:
In Tundra climatic region as most of the times of the year temperature remains below freezing point, trees cannot grow. Mosses, shrub, birch, juniper, alder grow in summer when ice melts: In summer ground surface remains frozen. Wet land is formed due to accumulation of rain water on the ground surface. Mosses, lichens, different types of flowers bloom in the wetland. In the landmass of Tundra sledge dog, arctic fox, polar bear, caribou are seen. In coastal region seal, whale, walrus and different types of fishes are found.

Question 18.
Describe inhabitant’s lifestyle of Tundra climatic region.
Answer:
In Tundra region due to adverse climate, hardy lifestyle this area is sparsely populated. Here inhabitants set up their lives fighting with nature. Eskimos, Red Indians.Samoyeds, Yakutus, Lappas, Fin people live here. For severe cold agriculture is not possible here. The inhabitants roam from one place to another place. During winter they live in a round shaped house Igloo. It is made of ice. In summer when ice melts away they make tents tupics made of seal’s skin. For transportation they use wheelless sledges and the boat kayak made of seal’s skin. They use the skin of animals in making their clothes and bones for weapons. They hunt seal, bear, reindeer. arctic fox and catch fishes from sea for livelihood. Milk of reindeer and berry fruits are their favourite food.

Question 19.
Mention the recent changes in Tundra climatic region.
Answer:
Recently some mining areas are found here. Coal from Pittsburgh, iron-ore form Kiruna, gold and mineral oil form Alaska and Ukraine. So, a few industries have developed here. Connection with outerworld has increased through railways and water ways. Railway communication from Murmansk port of Siberia to Saint Petersburg has been established. Alaska highway of North America has connected Tundra region with the other parts. In some parts agriculture is done with the latest technology by greenhouse. Inhabitants of this region import tea, coffee, tobacco against fleece and feather of animal. Nowadays inhabitants are habituated with modern lifestyle.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 5 Cloud and Rain offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 5 Question Answer – Cloud and Rain

Textbook Page no. 47.

Question 1.
By which process does the air heat up in case of convectional rainfall?
Answer:
The sun rays fall vertically on those regions where convectional rainfall occurs and for this reason the air hots up by the process of covection.

Question 2.
Why do ever green forests grow in the equatorial region?
Answer:
Ever green forests grow in the equatorial region because the sun rays fall vertically here through out the year. As the water mass is more in this region the amount of water vapour in air is more. As the result convectional rainfail occurs and evergreen forests have grown.

Question 3.
Name two countries that experience convectional rainfall through out the year.
Answer:
The two countries that experience convectional rainfall through out year are India and Bangladesh.

Textbook Page no. 4

Question 1.
Why does a barefoeted morning walk on the grass make your feet wet in winter?
Answer:
A barefooted morning walk on the grass make our feet wet in winter because dew drops accumulate on the grass.

Question 2.
why is less dew observed in dry region?
Answer:
In the dry region as the cold wind in the layer of atmosphere is less the water vapour near the earth surface become comparetively less cool and condensed. So less dew is observed in dry cegion.

Question 3.
Why is fog mainly seen in winter and on water bodies?
Answer:
In winter the amount of water vapour is more mainly on the water bodies. These water vapour condenses around the dust particle to form the fog.

Question 4.
What type of rainfall is generally observed in our country in the monsoon?
Answer:
In our country generally cyelonic rainfall occurs in monsoon.

Question 5.
why is the amount of water vapour are different in different areas?
Answer:
The temperature of air is different in different areas. Some areas have cool climate some have moderate. Some areas are surrounded by the mountains. The Sun rays fall vertically in some places, whereas squinting in other places. So the amount of water vapour are different in different areas.

Class 8 Geography Chapter 5 Question Answer West Bengal Board – Cloud and Rain

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
The word ‘oros’ means-
i) rain
ii) rock
iii) mountain
iv) river
Answer:
iii) mountain

Question 2.
The name of the cyclone of Bay of Bengal is-
i) cyclone
ii) Aila
iii) Typhoon
Answer:
i) cyclone

Question 3.
The cyclone that occured in 2009 is-
i) cyclone
ii) Aila
iii) Phailin
Answer:
Aila.

Question 4.
Combined form of water droplets and ice particles is called-
i) sleet
ii) cloud
iii) water vapour
Answer:
sleet.

Question 5 .
The distance between Cherrapunji and Shilong is-
i) 85 km.
ii) 56 .km.
iii) 58 km.
iv) 50 km.
Answer:
ii) 56 km.

Question 6.
The average maximum height of low cloud is-
i) 5,000 ft.
ii) 5,600 ft.
iii) 6,000 ft.
iv) 6,500 ft.
Answer:
iv) 6,500 ft.

Question 7.
The cloud with fibrous appearance is-
i) cumulus
ii) cirrocumulus
iii) cirrus
iv) altostratus
Answer:
iv) altostratus.

Question 8.
Mackerel sky is called when the sky is covered in-
i) cirrocumulus cloud
ii) cirrus cloud
iii) Altostratus cloud
iv) stratocumulus cloud
Answer:
i) cirrocumulus cloud

Question 9.
A vertical cloud is-
i) cumulus
ii) cirrus
iii) stratus
Answer:
i) cumulus

Question 10.
cumulonimbus looks like-
i) wooly
ii) dome
iii) light film
Answer:
ii) dome

Question 11.
From cumulonimbus cloud occurs-
i) Drizzle
ii) hailstorm
iii) snow fall
Answer:
ii) hailstorm

Question 12.
Cloud is formed in the laye –
i) Atmosphere
ii) Magnetosphere
iii) Troposphere
Answer:
iii) Troposphere

Question 13.
Which is not precipitation-
i) hailstorm
ii) rain
iii) Fog
Answer:
iii) Fog.

Question 14.
The instrument for measuring rain is-
i) animometer
ii) rain gauge
iii) barometer
Answer:
ii) rain gauge

Question 15.
Tiny droplets foating around like smoke is called-
i) fog
ii) dew
iii) smog
Answer:
i) fog

Question 16.
The diameter of tiny water droplets is-
i) 0.06 mm.
ii) 0.00 mm.
iii) 0.05 mm.
iv) 0.2) mm.
Answer:
iii) 0.05 mm.

Question 17.
From stratus cloud occurs-
i) Drizzle
ii) thunderstorm
iii) hailstorm
Answer:
i) Drizzle

Question 18.
Cyclone on East China is known as-
i) hurricane
ii) typhoon
ii) cyclone
Answer:
ii) typhoon

Question 19.
Cyclone is forward in both hemisphere in the latitude of-
i) 20°-25°
ii) 25°-30°
iii) 15°-25°
iv) 5°-20°
Answer:
iv) 5°-20°

Question 20.
The average annual rainfall of Cherrapunji is-
i) 2,250 mm.
ii) 11,777 mm.
iii) 2,207 mm.
iv) 10,767 mm.
Answer:
ii) 11,777 mm.

Question 21.
The imaginary line joining place with some average amount of precipitation is called on-
i) isotherm
ii) isohyet
iii) isopress
Answer:
ii) isohyet.

Question 22.
Which of the wids join together in cyslonic rainfall-
i) North-East and South-East trade wind
ii) North-South and South-West trade wind
iii) South-West trade wind
Answer:
i) North-East and South-East trade wind.

Fill in the blanks : (1 mark for each question)

1. The cloud that forms thin white film is called _______.
2. Cirrocumulus cloud make the sky iook like the _______ body of _______ fish.
3. The average height of medium clouds is ________ fit te ________ ft.
4. _______ cloud generally forecasts lingering rain.
5. _______ cloud is a layered cloud.
6. The other name of strotscumulus cloud is _________.
7. Stratus cloud is white to coloured and covered the entire sky like ____.
8. Accumulation of stratus cloud causes a great problem for _______ and ______.
9. Stratus cloud can sometimes cause a _________.
10. _______ cloud indicates bad weather.
11. The top surface of cumulus cloud is white, irregular and undulating like a while the bottom is black and _________
12. Cumulonimbus may be grey or ______ and is somewhat ________.
13. Cumulonimbus has a great vertical extent of about __________ f f upward from the layer of air adjacent to the surface of the earth.
14. Cumulonimbus cloud causes violent ________ and torrential-
15. The other name of cumulonimbus cloud is _________.
16. The diameter of the water droplets in cloud is ________.
17. In the layer of __________ the cloud forms.
18. The changing of water into water vapour is __________.
19. The tempereature at which the air gets saturated is its ________.
20. The changes of water vapour into droplets is called ___________.
21. Water droplets descending from the atmosphere to the surface of the earth in the influence of ________ is called ___________.
22. Cloud is the collection of small ___________.
23. ___________ rainfall is restricted to a small areas.
24. The rainfall that occurs for gettting obstructed by the mountain is called ____________.
25. The slope of the mountain along which the wind descends is the _______ side.
26. The leeward slope is called _______ region.
27. The sunrays fall _________ on the equatorial region through out the year.
28. _________ is located in the Hills of Meghalaya.
29. The ________ rainfall that caused by a cyclone is called _______ Rainfall.
30. The __________ sea branch of the south-west monsoon wind strikes the Western Ghats and causes abundant on its western slope.
31. ‘Aila’ occured in _______.
33. A combined form of _________ and ice particles is called ___________.
34. _________ causes some damage to crops and weakly constructed structures.
35. Hailstorm are sometimes seen in West Bengal during _______ or _________.
36. In high mountain region ____ wind is cooled to a temperature below freezing point the water vapour is directly converted to _________.
Answer:
1. cirrostratus
2. scaled, mackerel
3. 6.500:20,000
4. Altostratus
5. Stratocumulus
6) Bumpy cloud
7. grey, fog
8. mountaineers. pilot
9. drizzles
10. Nimbostratus
11. cauliflower, flat
12. whitish grey, black, dome shaped
13. 12.000
14. Thunderstorm, rain
15. Thunder cloud
16. 0.02 mm
17. Troposphere
18. evaporation
19. dew point
20. condensation
21. gravitational pulI. precipitaion
22. droplets of water
23. convectional
24. orographic
25. beward
26. rain shadow
27. vertically
28. Cherrapunji, Khasi
29. cyclonic
30. Arabian, rainfall
31. 2009
32. Typhoon
33. water droplets, sleet
34. Hailstorm
35. spring. summer
36. moisture laden, ice.

State whether True or False : (1 mark for each question)

1. More dew is formed on cloudless nights.
2. A combined form of water droplets and ice particles is called sleet.
3. Generally tropical cyclones are formed betwween 0° and 5° parallels of latitude in both hemisphere.
4. Average annual rainfall in Cherrapunji is approximately 6,637 mm.
5. The change of water vapour into water droplets is called condensation.
6. Cirrocumulus indicates bad weather.
7. Stratocumulus is called Bumpy Clouds.
8. Cumulus cloud is called thunder cloud.
9. Evaporation is the change of water into water vapour.
10. The temperature at which air gets saturated is its condeirsitiom
11. When a mountain or any upland stands in the path of moisture ladden wind from the sea, the wind is blocked in its path and rises alon the slope of the natural barrier.
12. Ornographic rainfall is called convectional rainfall.
13. The top surface of cumulus cloud is irregular and undulating like a cauliflower.
14. Hailstorms can occur from cumulus cloud.
15. Convectional rainfall generally takes place in the afternoon or evening and is usually torrential and thunderous.
16. Nimbostratus cloud indicates bad weather.
Answer:
1. true
2. true
3. false
4. false
5. true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14. fale
15. true
16. true

Match the column A with column B.

Column A	Column B
a) Rainfall is the most familiar example	i) indicates fair weather
b) Cumulonimbus cloud may be	ii) different names at different locations
c) Cirrus cloud generally	iii) Rain Shadow Region
d) Cirrocumulus cloud is called	iv) to crops and weakely costructed structures
e) Blue sky can be seen	v) is called Cyclonic Rainfall
f) Leeward slope is known as the	vi) whitish grey or black
g) Fog can sometimes reduce	vii) of precipitation
h) Hailstorm cause some damage	viii) visibility to a afew metres
i) Tropical cyclones are known by	ix) through the gaps in Altostratus cloud
j) Rainfall caused by a cyclone	x) the Mackerel Sky

Answer:
a) Rainfall is the most familiar example of precipitation.
b) Cumulonimbus cloud may be whitish grey or black.
c) Cirrus cloud generally indicates fair weather.
d) Cirrocumulus cloud is called the Mackerel Sky.
e) Blue sky can be seen through the gaps in Altostratus cloud.
f) Leeward slope is known as the Rain Shadow Region.
g) Fog can sometimes reduce visibility to a afew metres.
h) Hailstorm cause some damage to crops and weakely costructed structures.
i) Tropical cyclones are known by different names at different locations.
i) Rainfall caused by a cyclone is called Cyclonic Rainfall.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
What is the height of the highest cloud?
Answer:
20,000 feet.

Question 2.
What is the name of white, light and feathery cloud?
Answer:
Cirrus cloud.

Question 3.
How does the cirrocumulus could look like?
Answer:
cotton wool type.

Question 4.
How does the Altostratus cloud look like?
Answer:
Grey to bluish in colour with fibrous appearance.

Question 5.
Name some clouds with medium height.
Answer:
Altostratus and Altocumulus.

Question 6.
What is the other name of Stratocumulus?
Answer:
The other name of Stratocumulus is Bumpy cloud.

Question 7.
From which cloud rainfall with violent thunderstorms occurs?
Answer:
cumulonimbus.

Question 8.
What is the other name of cumulonimbus?
Answer:
Thunder cloud.

Question 9.
How is the cloud formed?
Answer:
The water of the sea, pond, river is heated by the sunrays and turn into water vapour. Then it accumulates the dust particle to form cloud.

Question 10.
In which layer of earth the cloud is formed?
Answer:
The cloud is formed in Troposphere of air.

Question 11.
What is evaporation?
Answer:
The process by which water is turned into water vapour.

Question 12.
What is saturated air?
Answer:
When a specific quantity of air holds the maximum amount of water vapour that it can hold a specific temperature, it is said to be saturated.

Question 13.
What is the diameter of general droplets of cloud?
Answer:
0.02 mm.

Question 14.
What are the different types of rainfall?
Answer:
There are the three types of rainfall-i) Convectional, ii) Orographic, iii) Cyclonic

Question 15.
What is windward side?
Answer:
The slope along which wind ascends and causes rainfall is the windward slope.

Question 16.
What is leeward slope?
Answer:
The slope along which the wind descends is called the leeward slope.

Question 17.
Name a ‘Rain shadow Region’.
Answer:
Meghalaya plateau.

Question 18.
What is the distance between Cherrapunji and Shillong?
Answer:
The distance between Cherrapunji and Shillong is 56 Km.

Question 19.
What is the average annual rainfall of Cherrapunji?
Answer:
11.777 mm.

Question 20.
What is the average annual rainfall of Shillong?
Answer:
2,207 mm.

Question 21.
What is the name of the cyclone of 2009 ?
Answer:
Aila.

Question 22.
What is the name of the cyclone of 2013 ?
Answer:
Pheilin.

Question 23.
What is the name of the cyclone found in the Bay of Bengal?
Answer:
Cyclone.

Question 24.
What is called the cyclone of Caribean sea?
Answer:
Hurricane.

Question 25.
What is ‘sleet’?
Answer:
A combined form of water droplets and ice particles is called sleet.

Question 26.
When is the rainfall occured in West Bengal?
Answer:
Rainfall is occured in West Bengal in rainy season.

Question 27.
Which instrument is used for measuring rainfall?
Answer:
Rain gauge.

Short Questions & Answers : (2 marks for each question)

Question 1.
What is fog?
Answer:
When water vapour in the air near the carth”s surface condenses around dust particles in it and forms tiny droplets of water, they float around and appear like smoke. This is called fog.

Question 2.
What does the term ‘Orographic’ mean?
Answer:
‘Oros’ means mountain. The word ‘Orographic’ derives from the fact that a mountain or any other upland stands in the way of wind and helps to cause rainfall.

Question 3.
What is ‘Hailstorm’?
Answer:
For the ascending air current the water particles sometimes rise high and getting cooled turn into little particles of ice. When more droplets of water gather around the ice particles their volume expands and fall with the rain. This is called ‘Hailstorm”.

Question 4.
What is convectional rainfall?
Answer:
The amount of evaporation is more in those arears where the sunray falls vertically through out the year and the water mass is more than landmass. The water vapours condense into tiny droplets and accumulate around the dust particle to form cloud. The rainfall that occur from this cloud is called the convectional rainfall.

Question 5.
What is Orographic rainfall?
Answer:
The wet moisture laden wind from the sea gets obstructed, goes high up. As it goes high it becomes cool and expanded. Then it condenses and causes rainfall. This is called Orographic rainfall.

Question 6.
What is ‘Rain shadow’ area?
Answer:
After raining heavily in windward side when the air reaches in the leeward side the amount of water vapour reduces. As the air descends, it gets heated and the capacity of holding water vapour increases. So the air becomes unsaturated and rainfall does not occur from such air in leeward side. Thus it is called Rain Shadow area or region.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write about the origin of clouds.
Answer:
Water evaporating from seas, rivers and ponds on being heated up by sunlight is a source of water vapour in air. Transpiration from plants is another source. When air is laden with water vapour it becomes lighter and moves upward easily. Lower air pressure in higher altitude makes the moister laden air expand. The air also cools down in contact with the cooler air at higher altitude. Gradually the temperature of the moist air mass reaches its dew point and the air becomes saturated. When the saturated air cools down further, the water vapour in it condsnces to form small droplets of water. These water droplets settle around particles of dust, salt and other solid substances suspended in air and float in the air as cloud.

Question 2.
What is precipitation?
Answer:
Water droplets descending from the atmosphere to the surface of the air in the influence of gravitational pull is called precipitation. Clouds sailing in the sky are actually innumerable small droplets of water collected around dust particles. These clouds can be condensed further when they rise and come in contact with colder air. This is how the small droplets get together to form larger drops of water. These larger drops are too heavy to be held in suspension to the air. They respond to the attraction of gravity and are brought down as rain.

Question 3.
Write about cyclonic rainfall.
Answer:
If temperature increases in a small area, air over it warms up and rise. This leads to lowering of the local pressure and the formation of a centre of deep depression. The air surrounding this low pressure centreis cooler and exerts high pressure. Wind blows from the high pressure areas to the central low pressure at great speed, thereby generating a cyclonic storm. This is how a tropical cyclone forms. When the wind reaches the central low pressure cell, it gets warmer and a whirlwind starts moving upwards. This centripetal ascending air mass cools down and condenses causing torrential and thunderous rain. Rainfall thus caused by a cyclone is called Cyclonic Rainfall.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 4 Pressure Belts and Winds offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 4 Question Answer – Pressure Belts and Winds

Textbook Page no. 36.

Question 1.
From which direction do Westerlies blow in the Southern hemisphere and what is the name given to such winds?
Answer:
At the time of blowing from southern Tropical High pressure belt to southern subpolar low pressure belt the Westerlies turns to the left according to Ferrell’s Law. Then it is known as North-West Westerlies.

Question 2.
Why are the Westerlies faster in the Southern hemisphere?
Answer:
The world masses are more than land masses in southern hemisphere and so the Westerlies blows faster here.

Question 3.
From which direction does the Polar wind blow in the Southern hemisphere according to the Ferrell’s Law and what is its called?
Answer:
In Southern hemisphere the wind blowing form south pole and turns to the left and it is known as south-east Polar wind.

Question 4.
why is Polar wind cold?
Answer:
Polar wind generates from extremely cold region. So which region the wind passes through the temperature decreases.

Textbook Page no. 37.

Question 1.
Which winds bring rain to China in Asia, Etheopia in Africa and Mexico in North America?
Answer:
For the influence of Westerlies.

Textbook Page no. 39.

Question 1.
which wind brings more rainfall to coastal areas?
Answer:
Sea wind brings more fainfall to coastal areas.

Question 2.
Which wind would help boats sail as they venture out into the sea or river at dawn?
Answer:
With the help of Landwind.

Question 3.
From which direction would the cool breeze come in a coast or a river bank in the evening?
Answer:
From the sea.

Textbook Page no. 40.

Question 1.
Why is there almost no rainfall from the winter Monsoon Wind?
Answer:
In winter dry cool wind blows from the land to sea. Thus rainfall does not occur.

Question 2.
Why is monson wind elassified as periodic wind?
Answer:
Monsoon wind blows in a certain season of the year, certain time of the day for the variation of the temperature. So it is called Perodic Wind.

Class 8 Geography Chapter 4 Question Answer West Bengal Board – Pressure Belts and Winds

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
The region extends through 50 of latitude to the north and south of the equator is –
i) Equatorial region
ii) Polar region
iii) Tropical region
Answer:
i) Equatorial region.

Question 2.
The other name of equatorial region is-
i) Coriolis
ii) Doldrums
iii) Horse Latitudes
Answer:
ii) Doldrums

Question 3.
The region between 25° and 30° parallels of latitude in the Northern and Southern Hemisphere is called-
i) Subpolar region
ii) equatorial region
iii) Tropical calm zone
Answer:
iii) Tropical calm zone.

Question 4.
The temperature of two poles remains the ice point throughout the year-
i) over
ii) below
iii) within
Answer:
ii) below.

Question 5.
Two tropical region between 250 and 300 parallels of latitude is known as-
i) Horse Latitude
ii) Coriolis
iii) equatorial region
Answer:
i) Horse latitude.

Question 6.
The difference between the air pressure of two regions is responsible for-
i) changing the direction of wind
ii) changing the speed of the wind
iii) blowing wind
Answer:
iii) blowing wind

Question 7.
The scientist who first said about the deflective force is-
i) G. G. Coriolis
ii) M. Sen
iii) Willium Ferrell
Answer:
i) G. G. Coriollis.

Question 8.
Buys Ballot Law was introduced in-
i) 1855
ii) 1856
iii) 1850
iv) 1857
Answer:
iv) 1857

Question 9.
Dry cold polar winds blow from high pressure belt to low pressure belt
i) all through the year
ii) sometimes
iii) periodically
Answer:
i) all through the year.

Question 10.
Westerlies blow in the southern hemisphere than the northern-
i) faster
ii) slower
iii) equally
Answer:
i) faster.

Question 11.
Westerlies blowing with a violent howl along the 60 south parallel of latitude is-
i) Roaring Forties
ii) Furious Fifties
iii) Screaming Sixtics
Answer:
iii) Screaming Sixties.

Question 12.
In the Northern hemisphere Polar winds blow between 70° N and 80° N-
i) latitude
ii) longitude
iii) not any of them
Answer:
i) latitude

Question 13.
The apparent migration of the sun occurs within-
i) 22nd. March-21st. June
ii) 22 nd. Sep.-21st. July
iii) 22nd Dec.-21st.June
Answer:
iii) 22nd. Dec. 21st. June

Question 14.
In agriculture the coasts of the Mediterranean sea are-
i) under-developed
ii) well-developed
iii) medium
Answer:
ii) well developed.

Question 15.
The Tundra Region is completely covered in ice for-
i) 7-8 months
ii) 6-7 months
iii) 8-9 months
iv) 3-4 months
Answer:
iii) 8-9 months.

Question 16.
The temperate grass land that located in the central and eastern parts of the continents are called-
i) Havard grassland
ii) mangrove forests
iii) Central Asian Steppis
Answer:
iii) Central Asian steppis.

Question 17.
The winds that blow particular time in the year is called-
i) periodic wind
ii) Local wind
iii) Sea brecze
Answer:
i) periodic wind

Question 18.
The cold wind blows from sea to land is called-
i) land breeze
ii) sea breeze
iii) Trade wind
Answer:
ii) Sea breeze.

Question 19.
At night the wind that blows from land to sea is called-
i) Trade wind
ii) perodic wind
iii) land breeze
Answer:
iii) Land breeze.

Question 20.
The another name of mountain wind is-
i) Anabatic wind
ii) Katabatic wind
iii) land breeze
Answer:
ii) Katabatic wind

Question 21.
The another name of valley wind is-
i) Anabatic
ii) Katabatic
iii) Parmanent wind
Answer:
i) Anabatic

Question 22.
Wind blowing in different parts of the earth at different times in the year due to local factors are called-
i) Land breeze
ii) Permanent wind
iii) Local wind
Answer:
iii) Local wind.

Question 23.
Pompero blows over-
i) Libiya
ii) Pampas region
iii) Guinea coast
Answer:
ii) Pampas region.

Question 24.
Chinook blows over-
i) Pampas region
ii) Guinea coast
iii) the eastern slope of Rocky mountain
Answer:
iii) the eastern slope of Rocky mountain

Question 25.
Harmattan blows over-
i) Guinea Coast
ii) Pampas region
iii) the Rocky. mountain
Answer:
i) Guinea coast

Fill in the blanks : (1 mark for each question)

1. The ______ region extends through 5° of latitude to the north and south of the equator.
2. The ______ movement of air over the earth’s surface is called air current.
3. The horizontal movement of air parallel to the earth’s surface is called ____
4. The two polar regions have temperature below _____ almost all through the year.
5. The two Tropical region is known as _____.
6. The rotation of the earth results in a force that causês an frèe flowing and mobile objects on earth to change direction and deflect. This deflective force is known as ______.
7. The American meteorolist _____ first mention the similarities swinging of clock with the swinging of provalent wind.
8. First _____ mentioned the coriollis Force .
9. The Coriollis Foree is mentioned in _____.
10. Buys Ballot Law is named after _______.
11. _____ are the winds blowing from Northern and Southern Tropical high pressure belt to the Equatorial low pressure belt through out the year.
12. The equatorial region where the North East and South East Trade wind meet is called ______.
13. _____ blow between 35° and 60° north and south parallels of latitudes.
14. The winds blow along 40° south parallels of latitude to the east is called _____.
15. Westerlies blowing with a violent howle among the 60° south parallel of latitude is called ______.
16. Extremely fast westerlies along the 50° south parallel of latitude is called ______.
17. With the variation of the parallels of latitude the temperature of air ______.
18. As the Trade wind blow from the less warm tropics to the warmer equatorial region, they get progressively ______.
19. The livehood of the people of ______ is rather difficult.
20. In winter watermass remains ______ than landmass.
21. The coasts of the Mediterranean sea are well developped in terms of ______ and ______.
22. The influence of Polar wind is found in ______ region.
23. ______ winds in both hemisphere blow from freczing cold regions to comparatively less region.
24. The ______ Region is completely covered in ice and has a lengthy spanning through 8-9 months.
25. At night the wind blows from ______ to sea.
26. The durinal difference in temperature between opposite seasons leads to the formation of ______.
27. The another name of ‘mountain wind’ is ______.
28. The another name of ‘valley wind’ is ______.
29. When the air pressure suddenlly drops over a small area, pressure is generally ______ in the centre.
30. In a cyclone wind speed can shoot up to about ______ km per hour.
31. Tropical cyclones are ______.
32. When the prevalent condition is just opposite to the cyclone, it is called ______.
33. Sirocco is one type of ______.
34. The word ‘chinook’ means ______.
35. Boro blows through the coast of the ______.
36. Fohn is one type of ______.
37. ______ is characterized by the dry and dusty northeasterly trade wind.
38. Fohn is found in the ______.
39. After the name of G. G. Coriolis the deflective force is called ______.
Answer:
1. equatorial region
2. vertical
3. wind
4. freezing point
5. Horse Latitude
6. Coriolis Force
7. William Ferrell
8. G. G. Coriollis
9. 1835 A.D
10. Buys Ballot
11. Trade wind
12. Inter Tropical convergence zone
13. Westerlies
14. Westerlies
15. Screaming sixties
16. Furious Fifties
17. varies
18. warmer
19. Sahara desert
20. warmer
21. agriculture, communication
22. Tundra
23. Polar, cold
24. Tundra, winter
25. Land
26. Monsoon wind
27. Katabatic wind
28. Arabatic wind
29. lowest
30. 160
31. destructive
32. anticyclone
33. local wind
34. snow eater
35. Adriatic sea
36. local wind
37. Harmattan
38. northern slope of Alps
39. Coriolis Force.

State whether True or False : (1 mark for each question)

1. Land breeze blows from the land towards the water at night.
2. Periodic winds are winds that blow during a particular time in the year.
3. Anticyclones are generally formed in low latitudes.
4. ‘Mountain wind’ is called local wind.
a. The he wind of rocky mountain is example of local wind.
6. Trade winds blow between 25° and 30° north and south parllels of latitude.
7. Wind is named after the direction fron which it flows.
8. William Farrel was a British scientist.
9. The equatorial region has more water than landmass.
10. Westerlies blows from the east.
11. Two air masses of opposite nature meet at the Tropics.
12. The wet hot polar winds blow throughout the year from polar low pressure belts to sub polar belts.
13. Periodic winds are winds that blow during a particular time in the year.
14. Tropical cyclones are constructive.
15. The higher slopes in Kulu and Kangra valleys are more populated than the valley floors.
Answer:
1. true
2. true
3. false
4. false
5, true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14. fale
15. true

Match the column A with column B.

Column A	Column B
a) Land breeze	i) the air is super cool and heavy
b) Sea breeze and Land Breeze	ii) tropics and the poles
c) Inter Tropical Convergence Zone	iii) meet at the Tropics
d) Coriolis Force acts generally	iv) different parts of the earth’s surface
e) In polar regions	i) occur everyday
f) The air is denser in the	ii) picks up speed at dawn.
g) Two air masses of opposite nature	iii) on the naturally flowing winds
h). Ships come to a stndstill	iv) is cold
i) Atmosphere pressure varies over	i) in the Horse Latitude
j) Polar wind	ii) is known as Equatorial calm region

Answer:
a) Land breeze picks up speed at dawn.
b) Sea breeze and Land Breeze occur everyday.
c) Inter Tropical Convergence Zone is known as Equatorial calm region.
d) Coriolis Force acts generally on the naturally flowing winds.
e) In polar regions the air is super cool and heavy.
f) The air is denser in the tropics and the poles.
g) Two air masses of opposite nature meet at the Tropics.
h) Ships come to a stndstill in the Horse Latitude
i) Atmosphere pressure varies over different parts of the earth’s surface.
j) Polar wind is cold.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
What is wind?
Answer:
The horizontal movement of air parallel to the earth’s surface is called wind.

Question 2.
What is air current?
Answer:
The vertical movement of the air over the earth’s surface is called air current.

Question 3.
Which region is called Doldrums?
Answer:
Equatorial calm zones.

Question 4.
Which region is called Horse-latitude?
Answer:
Tropical regions (25°-35°N. and S) are known as Horse-latitude.

Question 5.
How does the coriolis Force acts?
Answer:
Coriolis Force acts as a right angle to the direction of flow of wind.

Question 6.
How is the wind named?
Answer:
Wind is named after the direction from which it blow.

Question 7.
When was Buys Ballot Law find out?
Answer:
Buys Ballot law was found out in 1857.

Question 8.
What is the speed of Trade wind in Northern Hemisphere?
Answer:
Trade winds travel 16 km per hour in Northern Hemisphere.

Question 9.
What is ITCZ?
Answer:
The North East and South East Trade winds meet in the Equatorial Region. This is the Inter Tropical Convergence Zone or the ITCZ.

Question 10.
What is the other name of ITCZ?
Answer:
The other name of ITCZ is Equatorial calm region.

Question 11.
What is Roaring Forties?
Answer:
Westerlies blowing with a howl aiong the 40° south parallel of latitudes.

Question 12.
What is Furious Fifties?
Answer:
Extremely fast Westerlies along the 500 south parallel to latitude.

Question 13.
What is Screming Sixties?
Answer:
Westerlies blowing with a violent how along the 600 south parallel of latitude.

Question 14.
What is the source of the temperature of air?
Answer:
The source of air temperature is Sun.

Question 15.
How is the livehood of the people of Sahara desart for the influence of Trade wind?
Answer:
The ivehood here is rather difficult.

Question 16.
How is the livehood of the people of Mediterranean coast for the influence of westerlies?
Answer:
Prosperous in scope of employment.

Question 17.
Which region experiences blizzards for Polar wind?
Answer:
Siberia in Russia somctimes experience blizzards in polar wind.

Question 18.
When do the Periodic Winds blow?
Answer:
Periodic winds blow during a particular time in the year.

Question 19.
Where is the effect of Sea Breeze found?
Answer:
The effect of Sea-Breeze is found till 150 km. inland the coast line.

Question 20.
When the influence of Land Breeze increases?
Answer:
The influence of Land Breeze increases at dwon.

Question 21.
Which wind is called the larger verson of Sea and Land Breeze.
Answer:
Monsoon wind is cousdeered the larger verson of sea and I and Breeze.

Question 22.
Name two valleys of Himachal Pradesh.
Answer:
The two valleys of Himachal Pradesh are Kulu and Kangra.

Question 23.
Where is Chinook found?
Answer:
Chinook is found in Rocky mountain region of North America.

Question 24.
What does the term ‘Chinook’ mean?
Answer:
The term ‘Chinook’ means ‘Snow eater’.

Question 25.
What is the nature of Chinook?
Answer:
Chinook is dry and hot.

Question 26.
Where are the Cattles reared for the influence of Chinook?
Answer:
For the influence of Chinook the cattles are reared in Prairies.

Question 27.
Where is Fohn found?
Answer:
Fohn is found in Alps mountain region.

Question 28.
What is the nature of Fohn?
Answer:
Fahn is dry and warm.

Question 29 .
What happens due to the influence of Fahn?
Answer:
Due to the influence of Fahn the temperature rises.

Question 30.
How is Harmattan?
Answer:
Harmattan is dry and cold.

Question 31.
Where is Harmattan found?
Answer:
Harmattan blows over the Guinea coast from the eastern part of North West Anerica.

Question 32.
What is the Doctor wind?
Answer:
Harmattan is called the Doctor wind.

Question 33.
Why is Harmattan called the ‘Doctor’?
Answer:
It is because the wind provides relief from the warm moist and sultry wtither in the Tropical region.

Question 34.
How is Bora?
Answer:
Bora is dry and cold.

Question 35.
Where is Bora found?
Answer:
Bora blows through the coast of the Adriatic sea after descending along the southern slope of Alps.

Question 36.
What happens due to the influence of Bora.?
Answer:
This excessive cold wind disrupts normal life is southern Europe along the coast of the Adriatic sea.

Question 37.
What is Pompero?
Answer: Pampero is one of a local winds.

Question 38.
Where is Pampero found?
Answer:
Pampero originates in the Southern parts of South America and blows over Pampas region.

Question 39.
How does Pampero effect on human life?
Answer:
For the influence of Pampero the life of the people becomes comfortable.

Question 40.
Where is Sirocco found?
Answer:
Sirocco is originated in Libyan desert of Africa and blows over Southern Europe.

Question 41.
What type of wind is Sirocco?
Answer:
Sirocco is dry, warm and dusty.

Question 42.
How is the coast of Africa influenced by Sirocco?
Answer:
For the influence of Sirocco the northern coast of Africa is dried up and covered with dust.

Question 43.
Give examples of local wind blowing in India.
Answer:
Loo and Andhi.

Question 44.
What is the speed of Trade Wind in southern hemisphere?
Answer:
The speed of Trade Wind in southern hemisphere is 22-30 km. per hour.Short

Short Questions & Answers : (2 marks for each question)

Question 1.
What is coriolis Force?
Answer:
The rotation of the earth results in a force that causes all free flowing and mobile objects on earth to change direction and deflect. This is called Coriolis Force.

Question 2.
What is Buys Ballot’s Law?
Answer:
When one faces the wind in the Northern Hemisphere pressure is more towards the right and lower on left. Just opposite condition is seen in the Southern Hemisphere.

Question 3.
Which wind is called winter Monsoon wind?
Answer:
In winter cold, dry, wind blows from landmass towards the ocean. This is called Winter Monsoon Wind.

Question 4.
Which is called Summer Monsoon Wind?
Answer:
In summer moisture laden wind blows from ocean towards the land. That is called Summer Monsoon Wind.

Question 5.
What is Anabatic Wind?
Answer:
Sometimes the air over the valley does not heat up as much as that over the slopes flanking the valleys during day time. Therefore, the air pressure is comparatively highrer whereas the temperature is lower in the valley.nAir from the valley rises along the slopes. This is known as Anabatic Wind.

Question 6.
What is Catabatic Wind?
Answer:
At night the slopesradiate heat faster as the air over the mountain slopes cools down and high pressure prevails here. This heavy air from the high pressure descends and settles down in the valley. This is known as Catabatic Wind.

Question 7.
What is meant by periodic Wind?
Answer:
There are some winds that blow during a particular time in the year or a particular time of the day. These winds do not blow throughout the year like the planetary winds. These are called periodic winds.

Question 8.
What is Doldrums?
Answer:
In equatorial region upward air current is observed. There is no horizontal movement of air. This leads to the prevalence of calm conditions. So this is the zone of equatorial calm. This region is called ‘Doldrums’ which mean calm.

Question 9.
What is Sub-tropical regions?
Answer:
The region between 25° and 30° parallels of latitude in the Northern and Southern Hemispheres are respectively called the Northern sub-tropical and Southern sub-tropical regions.

Question 10.
Mention three segments of Inter Tropical Convergence Zone.
Answer:
The segment extending through the indian Ocean and the Pacific Ocean is the largest one. The second segment is found to the west of Africa in the Atlantic Ocean. The third segment is also on the pacific Ocean to the west of South America.

Question 11.
How trade winds get such name?
Answer:
Ancient commercial vessels used these winds in their sails to carry the cargo along certain marine routes. These winds them in trading. So these winds got their name as trade wind.

Question 12.
Mention the features of Sea breeze and Land breeze?
Answer:

1. Sea breeze and Land breeze occur everyday.
2. These winds blow at a regular interval each day.
3. Generally the effect of these winds are found till 150 Km. inland from the coastline.

Question 13.
How cyclone is formed?
Answer:
When air pressure suddenly drops over a small area, pressure is generally lowest at the centre. Then wind blows at high speed towards the central low pressure zone from higher pressure. this is called cyclone.

Long Questions & Answers : (3 marks for each question)

Question 1.
Why are the pressure belts formed?
Answer:
The hot and wet air of equatorial region rises up. The temperature reduces as the air rises up. On cooling the weight and density increases. The cool and heavy air sinks in the Northern and Southern Tropical region. Cool and dry air from polar region also sinks dwon in these two Tropical regions. Two air masses of defferent characters meet at the Tropic and the mass and density of air increase.

Question 2.
What is Horse Latitude?
Answer:
In sixteenth century ship from West Indies and Europe used to come stand still in Northern and Southern Tropical region because there was no air in their soil. The vessels carrying horses used to take much time to reach the West Indies and America. To avoid the crises of food and water the crews sacrificed some of the horses by throwing them into the Atlantic Ocean for reducing the weight of the ship. Therefore the Tropical regions are called the Horse latitudes.

Question 3.
What is Cyclone and Anti cyclone?
Answer:
When air pressure suddenly drops over a small area a low pressure creates at center and a high pressure creates at the surrounding zoncs. In the situation air blows from high pressure area to low pressure area. This is called cyclone.

When temperature of an area drops suddenly the air pressure increases. Then high pressure creates at the centre and a high pressure creates at the surrounding zones. In this situation air blows from centre to outwards. As the condition is just opposite of that of cyclone. So it is called the Anti cyclone.

Question 4.
Describe Ferrell’s Law.
Answer:
One type of force acts on any free flowing object on the earth for the revolution of earth. This deflects the direction of the moving objects. At the time of flowing from high pressure zone to low pressure zone the wind deflects towards right in the Northern hemisphere and to the left in Southern hemisphere for this reason. This is known as Ferrell’s Law.

Question 5.
What is Summer Monsoon wind and Winter monsoon wind?
Answer:
Monsoon winds blows through the Indian peninsula. In summer when the land get heated quickly by the sunrays the low pressure belt creates. But the water of Indian ocean remains cooler then and high pressure creates over there. Thus the moisture laten winds blows from ocean to land mass in :ummer which is called Summer Monsoon Wind.

In winter the landmass cools rcadily by radiating the sun heat and create high pressure belt over there. The water of Indian ocoan remains cooler, hotter then and low pressure belt creates there. Therfore, dry cool air tlows from land to sea in winter which is called winter monsoon wind.

Question 6.
What is permanent winds? Classify permanent winds. The winds that blow horizo”tally through out the year in the same direction at uniform speed are calied permanent winds.
Answer:
There are three types of permanent winds Trade wind, westerlies, Polar wints. Trade wind : The winds that blow from Northern and Southern Tropical high pressure belts to equatorial low pressere belt regularly, throughout the year are called Trade wind.
Westerlies : The winds that blow from Northern and Southern Tropikeal High pressure belt to Northern and Southern subpolar belts are called Westerlies. Polar winds The hot and dry winds blow from polar high pressure belt to subpolar low pressure belt in both hemisphere are called Polar wind.

Question 7.
What is Periodic winds? Compare Sea Brecze and Land Breeze.
Answer:
The winds that blow in a particular time in the year or a particuler time of a day are called Periodic winds.
Sea Breeze : The cool breeze that blows from sea to land in the afternoon or evening is called Sea Breeze. The difference between the air pressure of land and sea is responsible for the wind blowing.
Land Breeze : The land gets heated quickly and becomes cool by raducting the heat than the water mass. At night when the land entirely cools down the water still retain some heat and is warmer. A low pressure belt creates on the water and wind blows from land to sea at night which is called Land Breeze.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 3 Rocks offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 3 Question Answer – Rocks

Textbook Page no. 23.

Question 1.
Why are crystals not formed in sedimentery rocks?
Answer:
The hardness of the sedimentery rock is less than igneous rock. Therefore, sedimentery rocks do not have crystalline structure.

Question 2.
Why are fossils not found in igneous rocks?
Answer:
Due to excessive pressure and heat the inagma from earth’s interior comes out as lava and solidifies either on the earth’s surface or in the earth chamber to form igneous rock. So the fossil is not found.

Question 3.
From which type of rock is extraction of minerals convenient and why?
Answer:
In sedimentary rock mining is easy. Near about 7-10 crore years ago many organisms got burried under the layer of the sedimentary rocks. For the excessive pressure of upper layer and heat of the earth chamber the remaining parts of the body changes into the solution of hydrogen and carbon and different types of minerals are formed. So only the porous layer of sedimentery rock is called the store house of the minerals.

Textbook Page no. 26.

Question 1.
Which rocks are laid between and near a pair of railway tracks? Why are these rocks found here?
Answer:
In between railway track generally granite is found. It is because granite is very much resistant to erosion.

Question 2.
why does a piece of granite glitter?
Answer:
Glittering substance like mica is present in granite. This is because granite glitters.

Question 3.
Which rock is used to make a pencil lead?
Answer:
The lead of the pencil is made up of graphite, a metamorphic rock.

Question 4.
I am glittery, black or white. I am soft and malleable. I am a main constituent mineral of Granite. Can you say who I am?
Answer:
Quartz.

Identify me Page no. 27.

Question 1.
I have a smooth and attractive appearance. I am used in making floors. I have been used in constructing famous archetectural landmarks including the Victoria Memorial.
Answer:
Marble.

Question 2.
I am a very hard, fine grained grey black rock. I am commonly used in constructing roads. Water can easily pass through me.
Answer:
Gneiss.

Match the following :
Answer:

1. Limestone	Stalactite.
2. Sandstone	Sedimentary Rock.
3. Granite	Rounded dand form.
4. Great pressure	A cause of metamorphosis of rock.
5. Basalt	Flat topped landform.
6. Marble	Metamorphic rock.
7. Potassium	Plagioclase Feldsper.
8. Calcium Sulphate	Gypsum.

Class 8 Geography Chapter 3 Question Answer West Bengal Board – Rocks

Multiple Choice Questions& Answers : (1 mark for each question)

Question 1.
The characteristics of landform formed by Granite-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
iii) round.

Question 2.
The characteristics of landform formed by basalt-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
ii) flat.

Question 3.
The characteristics of landform formed by limestone-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
i) cave.

Question 4.
The characteristics of landform formed by sandstone-
i) cavesquare
ii) flatsquare
iii) roundsquare
iv) steep slope
Answer:
iv) steep slope

Question 5.
Slate is used in making-
i) cementsquare
ii) blackboardsquare
iii) iron industrysquare
iv) roads
Answer:
ii) blackboarc

Question 6.
Peat coal can be metamorphosed to graphite due to-
i) great pressuresquare
ii) chemical reactionsquare
iii) great heatsquare
iv) none of these
Answer:
iii) great heat

Question 7.
Amphibolite is the metamorphosed form of-
i) granitesquare
ii) sandstonesquare
iii) peat coalsquare
iv) mud stone
Answer:
i) granite

Question 8.
Victoria Memorial is made of-
i) granitesquare
ii) basattsquare
iii) mudstonesquare
iv) marble
Answer:
iv) marble

Question 9.
Fossils are found only in-
i) igneous rocks
ii) metamorphic rocks
iii) sedimentary rocks
Answer:
iii) sedimentary rocks

Question 10.
Sorrect metamorphosed form is-
i) graniterightarrow marble
ii) limestonerightarrow graphite
iii) sandstonerightarrow amphibolitesquare,
iv) basaltrightarrow amphibolite
Answer:
iv) basaltrightarrow amphibolite

Correct the wrong : (1 mark for each question)

Question 1.
The extrusive igneous rocks are generally fine grained because lavas after coming over the surface are slowly cooled and solidify.
Answer:
The extrusive igneous rocks are generally fine grained because lavas after coming over the surface are quickly cooled and solidify.

Question 2.
The amount of basic oxide in peridotite rock as 55%-45%.
Answer:
The amount of basic oxide in peridotite rock is more than 55%.

Question 3.
Andresite is one type of intrusive igneous rock.
Answer:
Andresite is one type of extrusive igneous rock.

Question 4.
Land forms developed on the regions of granite rock are mainly of round shaped.
Answer:
Land forms developed on the regions of granite rock are mainly of flat shaped.

Question 5.
The granite is composed of otvin and pyroxene.
Answer:
The granite is composed of mica and hornblends.

Question 6.
Igneous rocks are the store house of coal, petroleum and natural gas.
Answer:
Sedimentary rocks are the store house of coal petroleun and natural gas.

Question 7.
High permeability increases the water retaining capacity.
Answer:
High permeability reduces the water retaining capacity.

Question 8.
Fossil is found in metamorphic rocks.
Answer:
Fossil is found in sedimentary rocks.

Question 9.
Chemically formed sedimentary rock is conglomerate.
Answer:
Mechanically formed sedimentary rock is conglomerate.

Question 10.
Limestone is resistant to erosion and less permeable.
Answer:
Limestone is not resistant to erosion and highly permeable.

Question 11.
Bright crystalline structure is found in sedimentary rocks.
Answer:
Bright crystalline structure is found in igneous rocks.

Question 12.
Gneiss is harder than granite.
Answer:
Gneiss is less harder than granite.

Question 13.
The region predominated by limestone is suitable for constructing high rise building, roads etc.
Answer:
The region predominated by granite is suitable for constructing highrise building, roads etc.

Question 14.
Quartz is used for making glass.
Answer:
Quartz is used for cutting glass.

Question 15.
Mica is good conductor of heat and electricity.
Answer:
Mica is poor conductor of heat and electricity.

Question 16.
In Mah’s scale the value of harlness of diamond is 8.
Answer:
In Mah’s scale the value of hardness of diamond is 10.

Question 17.
The main element of plagioclase feldsper is Potassium.
Answer:
The main element of plagioclase feldspar is Sodium.

Question 18.
The main occupation of Chotanagpur plateau region is agriculture.
Answer:
The main occupation of Chotanagpur plateau region is mining and mine-based industry.

Question 19.
The soil derrived from basalt rock is infertile.
Answer:
The soil derrived from basalt rock is suitable for wheat and cotton.

Question 20.
The grains of sandy soil is smaller.
Answer:
The grains of sandy soil is bigger.

Question 21.
Sandy soil is found in North Indian plain.
Answer:
Alluvial soil is found in North Indian plain.

Question 22.
The fertility of clayey soil is more.
Answer:
The fertility of clayey soil is medium.

State whether True or False : (1 mark for each question)

1. In Mah’s scale the mineral with value of hardness 7 is Quartz.
2. Limestone disolves in water:
3. Sandstone is used in architectural works.
4. The colour of shale may be yellow, red, orange, pink etc.
5. Rocks can be metamorphosed in different ways.
6. When sedimentary rock metamorphosed it becomes brittle.
7. Marble is the metamorphosed form of limestone.
a. It is easy to mine from marble.
9. The metamorphosed form of sandstone is Qurartzite.
10. No landform is found in the limestone dominated region.
11. Feldspar is as smooth as slate.
12. Mica is used for making glass.
13. Regolith is the main composition of soil formation.
14. The soil made up of basalt is white.
15. The alluvial soil is the most suitable for agriculture.
Answer:
1 true
2. false
3. true
4. false
5. true
6. false
7. true
8. false
9. true
10. false
11. true
12. false
13. true
14 false
15. true

Fill in the blanks : (1 mark for each question)

1. __________ is a clastic rock.
2. Crystal may be __________ or hexagonal in shape.
3. Cometite is a _______ rock.
4. The diameter of the particle of gabbro is _________ mm.
5. The continental plate is made up of _________.
6. The chief constituent minerals of Basalt is _________.
7. __________ are found is sedimentery rock.
8. High _________ reduces the water retaining capacity of rocks.
9. ________ is the sedimentery rock of silicate.
10. The golden fort of Joysalmeer is made up of ___________.
11. Graphite is the _________ form of peat coal.
12. The example of a rock with fine grains is ___________.
13. Sedimentery rocks become less ________ when metamorphosed.
14. Marble readily melts in _________
15. ___________ is not as hard as ganite.
16. Sometimes lime formation may rise from the cave floors which is called ________.
17. For the construction high rise buildings and road the region with __________ is suitable.
18. Diamond is metamorphosed torm of __________.
19. Most of the rock forming minerals is made up of ________ eliment.
20. Mica may be of the white ____________.
21. Mica is _________ of heat and electricity.
22. ____________ is a hydrated crystal of Calcium Sulphate.
23. The influence of __________ is verv much evident in nature.
24. The soil predominated by Zypsum is soft and ___________ in colour.
25. The main occupation in Chotanagpur plateau region is mining and __________.
26. Characteristic features of a soil usually depend on the ____________ of the layer of rock underneath.
27. Soil derived from Basalt is suitable for growing ___________.
28. The soil derived from _________ is found in Chotanagpur plateat.
29. Grains of minerals are very _________.
Answer:
1. conglomerate
2. cubic
3. ultra basic rock
4. 3, 5. granite
6. Pyroxene
7. layers
8. permeability
9. flint
10. sandstone
11. metamorphose
12. mudstone
13. brittle
14. acid
15. granite
16. stalagmites
17, granite rock
18. carbon
19.8,20. muscovite
21. poor conductor
22. zypsum
23. mineral
24. light yellow
25. mining based industry
26. nature
27. wheat and cotton
28. granite
29. fine.

Match the column A with column B.

Column A	Column B
a) In igneous rocks	i) crosion resistant rock
b) Sedimentery rocks	ii) porous sedimentary rocks
c) Basalt is highly	iii) mainly from basalt
d) Sand remains loose and light	iv) crystalline structure is found
e) Shale is widely used	i) heat and electricity
f) Petrolium is available only in the	ii) are highly permeable
g) Constracting dams in a limestone	iii) of calcium sulphate
h) Black soil is made	iv) when it is dry
i) Gypsum is a hydrated crystal	i) terrain is not the right thing to do
j) Mics is a poor conductor of	ii) in making roof-tiles of buildings

Answer:
a) In igneous rocks crystalline structure is found.
b) Sedimentery rocks are highly permeable.
c) Basalt is highly erosion resistant rock.
d) Sand remains loose and light when it is dry.
e) Shale is widely used in making roof-tiles of buildings.
f) Petrolium is available only in the porous sedimentary rocks.
g) Constracting dams in a limestone terrain is not the right thing to do.
h) Black soil is made mainly from basalt.
i) Gypsum is a hydrated crystal of calcium sulphate.
j) Mics is a poor conductor of heat and electricity.

Very Short Questions& Answers : (1 mark for each question)

Question 1.
How can be igneous rock divided according to origin?
Answer:
According to origin igneous rock is of two types.

Question 2.
Name an extrusive igneous rock.
Answer:
Basalt.

Question 3.
Name a hypabyssal igneous rock.
Answer:
Dolorite

Question 4.
At what percent Silica is present in acidic rock?
Answer:
More than 60%.

Question 5.
What is the diameter of the particle of extrusive rock?
Answer:
‘ess than 1 mm.

Question 6.
At what amount basic oxide is present in acidic rock?
Answer:
More than 55%

Question 7.
How are the lasdforms developed with granite rock?
Answer:
Round shaped.

Question 8.
How are the land forms developed with basalt rock?
Answer:
Flat shaped.

Question 9.
What is the diameter of the particle of hypabyssal rocks.
Answer:
More than 3 mm.

Question 10.
Which rocks have high permeability?
Answer:
Sandstone.

Question 11.
In which rock layer mineral oil and natural gas are found?
Answer:
Only in porous sedimentary rock.

Question 12.
Name a sedimentary rock iron stone typed.
Answer:
Haematite.

Question 13.
What is rock?
Answer:
Rocks are homogenous or heterogenous aggregates of one or more minerals.

Question 14.
What minerals the granite rock is composed with?
Answer:
Granite rock is composed with quartz, feldsper. mica and hornblends.

Question 15.
What minerals the limestone is composed with?
Answer:
Limestone is composed with calcite.

Question 16.
What is petrology?
Answer:
The special branch of science which deals with the rocks and their characteristics is known as petrology.

Question 17.
What is mineralogy?
Answer:
The branch of science which deals with minerals is called mineralogy.

Question 18.
What is the other name of igneous rocks?
Answer:
The other name of igneous rock is primary rocks.

Question 19.
Why is the grains of extrusive igneous rock are generally fine?
Answer:
The grains of extrusive igneous rock are generally fine because lavas after coming over the surface are quickly cooled and solidified.

Question 20.
What are the different types of intrusive igneous rocks.
Answer:
The different types of intrusive igneous rocks are hypabyssal and plutonic.

Question 21.
What type of rock is dolerite?
Answer:
Dolerite is one type of hypabyssal igneous rock.

Question 22.
How are crystals formed in igneous rocks?
Answer:
Crystals are formed as the atoms of the mineral water which remain in like veins after cooling of the rock.

Question 23.
Name some crystals.
Answer:
Some crystals are quartz. topaz, calcite. diamond.

Question 24.
What is the shape of the crystal?
Answer:
Crystals are either crystal or hexagonal in shape.

Question 25.
Give an example of intermediate rock? What amount of basic acid is present in it.
Answer:
An example of intermediate rock is andesite in whiç basic oxide is 45-35%.

Question 26.
At what amount of Silica is present in peridotite rock?
Answer:
More than 45% of silica is present in peridotite.

Question 27.
What type of rock is kimberlite.
Answer:
Kimberlite is ultra basic rocks.

Question 28.
What is the diameter of Granite rock?
Answer:
The diameter of granite rock is more than 3 mm.

Question 29.
What are the rock forming minerals of basalt?
Answer:
The chief constituent minerals of basalt are feldspar, olivin and pyroxene.

Question 30.
What is the diameter of the particle of Micro-diorite?
Answer:
The diameter of the particle of micro-diorite is 1-3 mm.

Question 31.
What is permeability?
Answer:
Permeability means penetration of liquid and gaseous substances through the rock.

Question 32.
What is porosity?
Answer:
Porosity means the ratio between the voids and total volume of a given rock mas.

Question 33.
Give an example of pyroelastic rock.
Answer:
An example of pyroelastic rock is tuff.

Question 34.
Name a chemically formed sedimentary rock.
Answer:
A chemically formed sedimentery rock is Gypsum.

Question 35.
What is diatom?
Answer:
Diatom is organically formed sedimentary rock.

Question 36.
Name a calcareous sedimentery rock.
Answer:
Limestone.

Question 37.
What is the scientific name of limestone?
Answer:
Calcium Carbonate.

Question 38.
How is limestone used?
Answer:
Limestone is used as a raw material in making cement and in iron and steel industry.

Question 39.
With which stone the Khajuraho temple is made?
Answer:
The Khajuraho temple is made up of sandstone.

Question 40.
Which rock is used to make roof tiles?
Answer:
Slate is used to make roof tiles.

Question 41.
How is slate formed ‘slab?
Answer:
Under tremendous pressure slab metamorphoses to form slate.

Question 42.
What is phyllite?
Answer:
Phyllite is one type of slate.

Question 43.
Into which peat coal is transformed?
Answer:
Peat coal is transformed into Graphite.

Question 44.
Which rock is used for making black board.
Answer:
Slate is used for making black board.

Question 45.
Which rock is used for the construction of road?
Answer:
Metamorphic rock, Granite is used for the construction of road.

Question 46.
Name an acidic rock.
Answer:
An acidic rock is Basalt.

Question 47.
Is the Decan plateau is the part of Decan trap?
Answer:
The dalite like land from with flat top at Panchagani Mahabaleshwar region is the part of Decan trap of Decan plateau.

Question 48.
What is Stalactites and Stalagmites?
Answer:
Stalactites and Stalagmites are limestone cave.

Question 49.
Where is granite rock found?
Answer:
Granite rock is found in entire Chotanagpur region including Ranchi.

Question 50.
Why is constructing dams and reservoirs in a limestone terrain is not the right thing to do?
Answer:
It is because rivers or rain water can crode limestone by solution. So the dam may easily crack.

Question 51.
In which region multistoried buildings and excessive length of road are not advisable?
Answer:
Multistoried buildings and excessive length of road are not advisable in limestone terrains.

Question 52.
What is the colour of ortho claye?
Answer:
Pink.

Question 53.
Name the rock forming minerals.
Answer:
Silicon, Oxygen.

Question 54.
Which mineral is used for making ornaments and cutting glass and stone?
Answer:
Quartz.

Question 55.
What is the main element of Plagioclase feldspar?
Answer:
The main element of plagioclase feldsper is Sodium.

Question 56.
What is the element of orthoclase?
Answer:
The main element of orthoclase is Potassium.

Question 57.
What is the use of feldspar?
Answer:
Feldspar is used in glass and ceramic industry.

Question 58.
Name a soft mineral.
Answer:
Zypsum.

Question 59.
What is Malı’s scale?
Answer:
Mah’s scale of hardness measures the hardness of minerals.

Question 60.
What is the hardness of corundum measured in Mah’s scale?
Answer:
The hardness of Corundum in Mah’s scale is 9.

Question 61.
How is the soil in the region with Gypsum?
Answer:
The soil is soft light yellowish in the region with Gypsum.

Question 62.
Name a soil with excessive mineral.
Answer:
Laterite soil and red soil.

Question 63.
Why is the soil, made up of granite, red?
Answer:
This is because the oxide of iron present in this soil at high amount.

Question 64.
What type of soil found in the desertic area of Rajasthan?
Answer:
Sandy soil.

Question 65.
Where is Mangrove forest found?
Answer:
Mangrove forest is found at the sea coast with saline soil.

Short Questions & Answers : (2 marks for each question)

Question 1.
Mention one difference of homogeneus and heterogeneus mixture.
Answer:
In homogeneus mixture all elements remain in equal ratio everywhere but in heterogeneus mixture all the elements lie in equal ratio in different places.

Question 2.
What is fossil? In which rock fossil is found?
Answer:
Marine plants and animals sometimes come within the beds of the sediments during compaction of layers to form sedimentery rock. Later dead remains of the organism leave their imprint into the layers of sediment after being solidified. This is called fossils.

Question 3.
What is rock cycle?
Answer:
In nature the formation of rocks and transformation of rocks have occured in cycling way in a specific method. The complete cyclic process of formation of rocks and their changes frum one type to the other is called the rock cycle.

Question 4.
What is regolith?
Answer:
Natural agents like river wind, rainfall, sea-waves, glacier etc. degrade rocks and minerals over a long time to form loose deleres of rock. This delere’s then interacts naturally with water air and organic matter to form soil. This delere’s of degraded rocks is called regolith.

why the Chotanagur Plateau is called ‘the store house of minerals’.
Answer:
Chotanagpur Plateau in India is rich in minerals like iron, copper, bauxite, manganese, dolomite etc. So it is called the storehouse of minerals’.

Question 6.
What is limestone?
Answer:
Limestone is a calcareous sedimentary rock. It is not generally soluble in water. But it gets readily dissolved in rainwater or acid solutions when it is transformed to calcium bicarbonate. Limestone may be white, grey, green or blackish in colour.

Question 7.
What is sandstone?
Answer:
Sandstone is a sedimentary rock rich in sand. It is resistant to erosion in spite of being highly porous and permeable. Architects use it in making epitaphs and monuments. It is yellow, orange, red, pink, white or grey in colour.

Question 8.
What is Marble?
Answer:
Marble is the metamorphosed form of lime stone. It is smoothy, glittery and attractive. It is available in a wide variety of colours including white, green, grey, yellow and blue. It is extensively used by architects.

Question 9.
What is slate?
Answer:
It is the metamorphosed form of mudstone or shale. It is smooth and biuish grey to black in colour. It is arranged into thin layers and can be easily broken. They are used in making oof tiles and blackboards and can be used as a surface for writing.

Question 10.
What is gneiss?
Answer:
This is a hard and resistant rock. The minerals in it are often arranged in bands. So this is called a banded rock. Extarcting a certain mineral from it is thus convenient. This rock is widely used to make roads and in other constructions.

Question 11.
What is quarz?
Answer:
Quartz is very hard, often whitish and hexagonal crystals. It is the main constituent of granite and Basalt. These rocks are very resistant to erosion due to the presence of quartz in them. It is used as stone cutter, glass cutter and in ornaments.

Question 12.
What is mica?
Answer:
Mica is lustrous, smooth, flaky and brittle in nature. It may be of the 1 , hite Muscovite or black Biotite varieties. Its presence gives granite its luster. Mica is a conductor of heat and electricity. It is used in preparing electrical goods.

Question 13.
What is shale?
Answer:
It is a sedimentary rock rich in clay. It is blackish grey in colour. Thin layers are seen in it. It is soft snd brittle rock. This rock is widely used in making roof-tiles of buildings.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write a short note on Igneous Rock.
Answer:
It is also known as Primary rocks as these were the first rocks to originate on earth. This is also called primary rock. According to origin igneous rock is of two types Intrusive and Extrusive igneous rocks. Extrusive igneous rocks are generally fine grained besause lava after coming over the surfsce, is quickly cooled and solidified e.g-basalt, obsedian. When the rising magma foes not reach the earth’s surface, butis cooled and solidified below the surface of the earth, it is called intrusive igneous rock e.g-granite, dolerite.

Question 2.
Write a short note on sedimentary rock.
Answer:
Sediments and debris derived from the source through erosion snd transportation by natural agents of erosion like river, glacier, wind, sea waves are deposited under the water. Thus this types of rocks are called sedimentary rocks. Chalk, sandstone, mudstone are the example of sedimentary rocks. Layer and mud cracks are found in this rocks. Fossils are found in this rocks. These rocks are porous and also fragile. This type of rocks are highly permeable. Different sedimentary rocks have different degree of erosion resistant capacity. Sedimentary rock is the store house of coal, petroleum and natural gas. On the basis of composition sedimentary rocks are classifed into three groups i) mechanically formed sedimentary rocks, ii) Chemically formed sedimentary rocks, iii) Organically formed sedimentary rocks. Sedimentary are also classified according to the origin. Those are : i) Clastic rocks. ii) Non-clastic rocks.

Question 3.
Write a short note on metamorphic rock.
Answer:
Metamorphic rocks are formed by changing the physical and chemical characters of igneous and sedimentary rocks due to influence of great heat and pressure.
Metamorphic rocks may be crystalline. When an igneous change into metamorphic rocks, it is smoother, more lustrous and more crystalline. When a sedimentary rocks changes into metamorphic rocks it becomes less brittle. Besides, great heat and pressure erase out the fossils in a sedimentary rocks during metamorphism. Marble, slate are common metamorphic rocks.

Question 4.
What is rock cycle? Explain.
Answer:
The magma of asthenosphere comes out on the earth surface after eruption and flows of lava. Then cools to form igneous rock, or cools and solidify in the earth chamber to form igneous rocks. In due course of time the igneous rocks get eroded and accumulate under the sea, lake, ocean. After a long period of time this sediment changes this sedimentary rocks then this igneous rocks or sedimentary rocks change into metamorphic rock due to great heat, pressure or chemical reaction. Later for tiectonic movement the rocks may be brough back to interior of this earth where they melt and recycle as magma. Origin of rocks andtheir transformations and metamorphosis goes on in a cycle. The complete recycle process of formation of rocks and there change from one type to other is called the rock cycle.

Question 5.
What is the influence of mineral in soil?
Answer:
The influence of mineráls in nature is very distinct. The surface of the soil rich in iron and bauxite is very hard and red in colour. On the other hand soil, rich in Zypsum is soft and yellow in colour. Soil, rich in soft calcite, is erosion-prone. The places, where the mineral oil is found, are made up of porous, permiable sedimentary rocks. The soil with exclusive miniral is not fit for agriculture.

Question 6.
Write about formation of soil from rocks.
Answer:
For the action of different natural agents like river, wind, rainfall, ocean current, glacier current, the rock forming minerals are eroded and exist as the rock particle which mixes with water, air and different organic matter later and forms soil. The soil made up of basalt rock is black and is found in the Decan plateau region of India. The sandy soil is form in this that region with sandstone.

The colour of the soil is light, yellowish to grayish brown. The soil is not fit for agriculture. Sandy oil is found in the desertic region Rajasthan. In alluvial soil grains of the minerals are very fine. This type of soil is very fit for agriculture. The soil of North Indian plain is some in nature. The soil which is enrich with iron and Aluminium oxide excessively is called Laterite soil. This type of soil is not fertile. Laterite soil is found in Chota Nagpur and Meghalaya plateaus. Saline soil is found at the sea coast. Mangrove vegetation grows in this soil. This soil is found in the Sundarban region of West Bengal.

Question 7.
What is Karst Topography?
Answer:
There are natural caves in Cherrapunji-Mawsynram. Narrow, pointed, rocky structures hang from the seiling in these caves. These are limestone caves. The lime formations hanging from the roof are called Stalactites. Sometimes similar lime formations may rise from the cave floors. They are called Stalagmites. Rising Stalagmites and drooping Stalactites may join to form limestone pillars. This typical assemblage of landform is called Krast Topography.

Question 8.
Write three characteristics of igneous rocks.
Answer:
Three characteristics of igneous rocks-
i. Joints and cracks are very common in these rocks, so these are highly permeable.
ii. Crystaline structure is found.
iii. The Colour of these rocks vary from light to dark.

Question 9.
Write three characteristics of sedimentary rocks.
Answer:
Three characteristics of sedimentary rocks-
i. Layers and mudcracks are found in this type of rocks.
ii. Different sedimentary rocks have different capacity to resist c.osion.
iii. Reserves of coal, petroleum and natural gas are found within these rocks.

Question 10.
Write three characteristics of metamorphic rocks.
Answer:
Three characteristics of metamorphic rocks-
i. Metamorphism usually hardens igneous and sedimentary rocks.
ii. Igneous rocks get smoother, morelustrous and more crystalline with metamorplifsm.
iii. Sedimentary rocks become less brittle when metamorphosed.

Detailed explanations in West Bengal Board Class 8 Geography Book Solutions Chapter 2 Unstable Earth offer valuable context and analysis.

WBBSE Class 8 Geography Chapter 2 Question Answer – Unstable Earth

Multiple Choice Questions & Answers : (1 mark for each question)

Question 1.
J. T. Wilson introduced the word ‘Plate’ in-
i) 1965
ii) 1906
iii) 1970
iv) 1955
Answer:
i) 1965

Question 2.
Machenziae and Parker gave information on plate movement in-
i) 1967
ii) 1990
iii) 1965
iv) 1960
Answer:
ii) 1965

Question 3.
The vivid explanation of the plate tectonic theory was given by-
i) W. J. Morgan
ii) J. T. Wilson
iii) Alfred Wegener
Answer:
i) W. J. Morgan.

Question 4.
Asthenosphere lies –
i) 500-600 km below the crust
ii) 300-400 Km below the crust
iii) 200-300 kmbelow the crust
iv) 100-200 Km below the crust.
Answer:
iv) 100-200 Km.

Question 5.
Krakatua volcano has become active after-
i) 200 years
ii) 400 ycars
iii) 500 years
iv) 300 years
Answer:
i) 200 years.

Question 6.
The percentage of active volcano in the earth-
i) 10%
ii) 15%
iii) 20%
iv) 30%
Answer:
ii) 15%

Question 7.
The percentage volcanocs of the world are located in the middle of the plate on hot spot About-
i) 2%
ii) 3%
iii) 5%
iv) 8%
Answer:
iii) 5%.

Question 8.
The focus of the earthquake is located at the depth of –
i) 50-100 Km
ii) 100-150 Km
iii) 150-300 Km
iv) 200-250 Km
Answer:
i) 50-100 Km.

Question 9.
San Francisco was almost completely destroyed in a devastating earthsuake in-
i) 1910
ii) 1912
iii) 1904
iv) 1906
Answer:
1906

Question 10.
Percentage of earthquakes on the earth occur in the Pacific belt
i) 60%
ii) 70%
iii) 20%
iv) 40%
Answer:
ii) 70%.

Question 11.
Every year the powerful volcanic activities in the continental area are more than-
i) 20
ii) 10
iii) 40
iv) 50
Answer:
iv) 50.

Question 12.
The eruption of mount Pole occured in-
i) 1906
ii) 1202
iii) 1908
iv) 1905
Answer:
i) 1906.

Question 13.
Enormous loss of life and property took place due to the eruption of Mount St Helen in-
i) 1975
ii) 1980
iii) 1991
iv) 1900
Answer:
ii) 1980.

Question 14.
At the time of eruption many people die for-
i) cancer
ii) asthma
iii) suffocation
Answer:
iii) suffocation.

State whether True or False : (1 mark for each question)

1. The earth crust is made up of 18 small plate.
2. The outer mantle is located 300-400 Km. deep under the earth crust.
a. The temperature of asthenosphere is 1500° C.
4. The fold mountains are called ‘Young’.
5. The tectonic plates moved on asthenosphere.
6. popa of Mayanmar is a active volcano.
7. Primary wave is the fastest seismic wave and reaches the earth’s surface before all other waves.
8. The interior of the earth is still very hot.
9. Example of old fold mountain is Rocky.
10. Volcanism and earthquake are examples of sudden earth novements.
Answer:
1. false
2. false
3. true
4. true
5 true.
6. false
7. true
8. true
9. false
10. true.

Fill in the blanks : (1 mark for each question)

1. The temperature of asthenosphere is _______.
2. ______ is the deepest trench of the earth.
3. The divergent plate margin is called _______ plate margin.
4. The mountains are formed more than ______ years ago.
5. When the magma flows on the earth crust it is called ______.
6. The mountains like Himalaya Alps are formed ______ lack years ago.
7. ______ of earth is active volcano.
8. _______ is an alternative source of energy.
9. The epicentre of earthquake is ______ km deep.
10. In year ______ earth quake occur in
11. In 1906 the magnitude of the earthquake was _______.
12. ______ city was destructed in earthquake.
13. Earthquake takes place in earth at _________.
14. _____people had lost their life in Tsunami.
15. Damage and destruction was caused in ______ countries of South-East Asia.
16. On 26th January 2001 in _______ of Gujarat almost one lakh people lost their lives for severe earthquake.
17. Sudden of ______ earth the houses are broken.
18. Most of the active _______surround Pacific ocean as a ring.
19. The ring of earthquake in India is generally _________.
20. The magnitude of earthquake is measured by _________.
21. From the epicentre of the earthquake two types of wave spread out along the _____
22. Almost each and every ______ is earthquake prone.
23. Most of the focus of the earth quake located at the depth of _______ km.
24. ________ of N.ars is the highest voleanoes of the solar system.
25. A type of dense viscous lava comes out from the volcanoes of Indonesia which is known as _____ in Hawaiean language.
Answer:
1. 1500° C
2. Mariana
3. constructive
4. 3 – 4 millions of years
5. lava
6. 40
7. 15% Neutron
8. Geothermal energy
9. 50-100
10. 1955 kolce of Japan
11. 8.5
12. Sunfrancisco
13. 20%
14. 36000
15. 111
16. Bhuj
17. temor
18. Volcanoes
19. Himalaya mountain region
20. Seismograph
21. earth crust
22. margin of the plate
23. 50-100
24. Olympus Mars.
25. Aa.

Match the column A with column B.

Columu A	Column B
a. There are 6 major	i. at a rate of 10 cm/year
b. The earth’s crust is made of	ii. occur in Pacific Ring of Fire
c. Sometimes two plates move towards	iii. and 20 minor plates
d. Pacific Ocean plate is moving	iv. cannot be forecasted
e. The interior of the earth	v. due to an earthquake
f. 70 percent of all earthquake on the earth	vi. each other and collide
g. Unlike other natural disasters, an eartquake	vii. a few rigid and solid plates
h. Sometimes coastal land may be submerged	viii. is still very hot

Answer:
a) There are 6 major and 20 minor plates.
b) The earth’s crust is made of a few rigid and solid plates.
c) Sometimes two plates move towards each other and collide.
d) Pacific Ocean plate is moving at a rate of 10 cm / year.
e) The interior of the earth is still very hot.
f) 70 percent of all earthquake on the earth occur in Pacific Ring of Fire.
g) Unlike other natural disasters an eartquake cannot be forecasted.
h) Sometimes coastal land may be submerged due to an earthquake.

Very Short Questions & Answers : (1 mark for each question)

Question 1.
Which scientist introduced the term ‘Plate’?
Answer:
In 1960 Canadian geophysicist – J. T. Wilson introduced the term ‘Plate’.

Question 2.
Who gave information on plate movement?
Ans:
In 1967 Mekensil and Parker gave information on Plate movement.

Question 3.
Who gave vivid explanation of the Plate tectonic theory?
Answer:
In 1967 W. J. Morgan and Le Pichon gave vivid explanation of the plate tectonic theory.

Question 4.
What is the deepest trench of the world? In which ocean does it lie?
Answer:
The deepest trench in the world is Mariana trench. It lies in Pacific ocean.

Question 5.
How is Alps mountain formed?
Four in one (viii)-24
Answer:
Alps mountain is formed when African and Eurasian plates converged to each other.

Question 6.
Name the main fold mountain of the world.
Answer:
Most of the fold mountains of the world have formed for convergence of the continental plates. These are Applachian Ural Aravalli etc

Question 7.
What is Volcanic mountain?
Answer:
The mountains those are formed by deposition of volcanic material is called volcanic mountain. Example-Fujiyama of Japan.

Question 8.
When did the volcanism start?
Answer:
Volcanism started millions of years ago?

Question 9.
In which countries volcanism have occured?
Answer:
Volcanism have occured in Japan Italy India Indonesia etc.

Question 10.
How is the ‘process affecting earth’s crust’ is classified?
Answer:
The process affecting earth’s crust is classified into the types – (i) Endogenetic process (ii) Exogenetic process.

Question 11.
What is lava?
Answer:
The melted viscous substance of the earth’s interior is called magma and when it comes out on the earth surface it is called lava.

Question 12.
Which is the highest volcano of the solar system?
Answer:
Olympus Mons of the Mars is the highest (27 Km) volcano of the solar system.

Question 13.
What percent volcano on the earth is active?
Answer:
15% volcanoes on the earth is active.

Question 14.
What is earthquake?
Answer:
When energy trapped in the blastic interior of the earth is suddenly released the earth crust experience temors which is called earthquake.

Question 15.
In which year devastating earthquake occured?
Ans:
Devastating earthquake occured in 2004 300000 lives were lost and enormous damage causc d over 11 countries in south east Asia.

Question 16.
What is Seismograph?
Answer:
A Seisomograph is the instrument measuring the magnitude of an earthquake.

Question 17.
In which year earthquake occured in Chili?
Answer:
In 1960 earthquake occured in Chili.

Question 18.
What was the level of the scale of the earthquake of Chili??
Answer:
The level of the level of the scale was 8.5.

Question 19.
At what percent the earthquakes occur in the Mid Continental Belt?
Answer:
20% earthquakes occur in the Mid Continental Belt.

Question 20.
Name the volcanoes of ‘Pacific Ring of Fire’?
Answer:
The volcanoes of Pacific Ring of Fire are Fujiyama (Japan) Pinatubo (Philippines), Krakatau (Indonesia) St. Helen (USA) Popocate peti (Maxico) Cotopaxi (Equador) ete.

Question 21.
What is the similarity between volcanism and earthquake?
Answer:
Volcanism and earthquake are both sudden manifestations of endogenetic forces.

Question 22.
What contribute to an area being more prone to disasters?
Answer:
Worldwide increase of population unplanned urbanization construction of heavy multistoried buildings roads dams and reserviors and illegitimate mining – all contribute to an area being more prone to disasters.

Question 23.
How can earthquake form natural harbour?
Answer:
Due to earthquake sometimes coastal land may be submerged due to an earthquake thereby forming an natural harbour.

Question 24.
Give an example where mud island emerged from under the water due to earthquake.
Answer:
A ‘mud island’ has emerged from under the water off the Karachi coast.

Long Questions & Answers : (3 marks for each question)

Question 1.
Write a short note on voleanism.
Answer:
From the time of the creation of the earth the volcanic erruption is occuring for millions of years. At the time of volcanic erruption the hot matter materials ash gases etc comes out from the openings of the earth. After frequent erraption lava is accumulated around the mouth of the volcano forming a cone shaped mountain. This type of mountain is called volcanic mountain as it is formed by deposition of the volcanic material. For example – Fujiyama of Japan Vesuvious of Italy Barren of India Krakatoa of Indonesia. In different geological time the temperature of earth’s atmosphere has been controlled by the process of volcanisation and finally has reached present favourable condition.

Question 2.
How volcanism takse place?
Answer:
The interior of the earth is still extremely hot. Naturallyb rocks are supposed to melt in 2000° C temperature at mantle. But for the extreme pressure of the upper layer the melting point is increased. Thus the rocks melts partly become slipping and flows like plastic. In some part of outer mantle the rocks melts completely. The density of the melted rock is lower. It is lighter than other partially melted rocks of the surrounding. The pressure and the melting point of magma decreases proportionally with the rising upward of magma. The liquid portion of magma turns into gas and water vapours under extreme pressure. Then the magma comes out to the earth’s surface through the opening of earth crust.

Question 3.
How is the earth quake formed?
Answer:
Almost all plate margin in the earth are highly earthquake prone and so all the volcanoes and the centres of earthquake are lie at same place. Besides natural causes like tectonic slides earthquake can also occurs from artificial or non natural causes like digging of underground pits mines and tannels construction of reservoirs and bomb explosion.

Question 4.
What is Contiuental Drift Theory?
Answer:
According to the continental Drift Theory of Alfred Wegener-about 300 million years ago all the present day landmasses were united as a supercontinunt called pangea. Later on it began to break apart and the pieces direted in different directions. Actually the continental crust was floating over oceanic crust. But the Continental Drift Theory could not fully explain the causes of earthquake or formation of oceans countries and mountains volcanism.

Question 5.
What is the divergent plate margła?
Answer:
When two oceanic plates move away from each other hot molton magma comes upward from the earth’s interior and new oceanic crust and mid oceanic ridges are formed from the hot molten magma after getting cooled and solidified. This is called divergent plate margin.

Question 6.
What is Mariana trench?
Answer:
For the moving towards of each other of continental and oceanic plate heavy oceanic plate get submerged under the continental plate. As the result deep oceanic trench is developed in this way. Mariana trench of the Pacific is the deepest trench of the world.

Question 7.
What is divastating plate margin?
Answer:
When the molten materials come out from the interior along the plate margins several volcanoes and volcanic islands are formed along the subduction plate margin. As the earth quake and earth movements are the regular phenomena in this areas of the crust. This type of plate margin is called divastating plate margin.

Question 8.
What is Seismic waves?
Answer:
Energy generated by an eartinquake spreads out in the form of waves from the focus and the epicenter to other parts of the earth just like the radial surge of waves after a stone is dropped on water. These waves are called Seismic waves.

Question 9.
Classify the Seismic waves?
Answer:
Seismic waves are of three types.
a) Primary wave : It is the fastest seismic wave (6 Km / sec) and reaches the earth’s surface before all other waves. This wave travels through solid liquid and gaseous media through a push and pull process.
b) Secondary wave : It reaches the earth’s surface immediately after the primary wave (3-5 Km . sec ). This wave can not travel through liquid and gaseous media. It travels only through solids.
c) Surface waves or level waves: Two types of this wave (3-4 Km / sec) spread out from the epicenter of the earthquake along the eart’s surface. These waves are responsible for most of the damages caused by eartquakes.

Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 5D Biodiversity and Conservation offer valuable context and analysis.

WBBSE Class 10 Life Science Chapter 5D Question Answer – Biodiversity and Conservation

Short Snswer Type Questions : 2 Marks

Question 1.
What are the objectives of conservation.
Answer:
The objective behind conservation of living resources are as follows :

1. To maintain essential ecological processes and life supporting system.
2. To preserve the diversity of species or the range of genetic material found in the world’s organisms.
3. To ensure sustainable utilisation of species and ecosystems which support millions of rural communities as well as major industries.

Question 2.
How are forests useful for the protection of wall?
Answer:
Forests protect land by :

1. preventing soil erosion by wind and water and
2. by checking the velocity of wind or raindrops striking the ground and reducing dislodging of the soil particles.
3. The root systems firmly hold the soil.

Question 3.
State the role of forest in retaining sub-soil water.
Answer:
Role of forests in retaining sub-soil water :
(i) Forests add humus to soil which absorbs water during rains. It does not allow it to evaporate or run of quickly.

Question 4.
What steps are required for conservation of forest.
Answer:
Steps for conservation of forests :

1. Discourage the use of firewood, by providing alternative sources of energy like biogas etc.
2. Limit felling of trees for timber, combined with tree plantation.
3. Adopting modern forest management practices like optimization of silviculture, use of irrigation, fertilizers, bacterial and mycorrhizal inoculation, control of weeds, breeding of new varities and use of biotechnology.

Question 5.
Distinguish between the following :
Answer:

Question 6.
What is biodiversity?
Answer:
The variety of living organisms in an ecosystem is called biodiversity. The exact number of species in the world is not known. The taxonomists have described about 1.4 million species. But taxonomists estimate that there are 4 to 31 million more species. Much of these species are unnoticed.

Question 7.
What is MAB?
Answer:
Man and biosphere programme is an international biological programme of UNESCO (United Nations Educational Scientific and Cultural Organisation) which was started in 1971 but was introduced in India in 1986. MAB has studied human environment, impact of human interference and pollution on biotic and abotic environment and conservation strategies for the present as well as future.

Question 8.
What do you mean by hotspots of biodiversity?
Answer:
The concept of hotspots was developed by Norman Myers in 1988. These areas are rich in species diversity with high endemism and priority areas for in situ conservation because these areas are under constant threat. Endemism is the situation where particular species confined to a particular area and not found anywhere else. The key criteria for determining a hot spot are
(i) Number of endemic species.
(ii) Degree of threat which is measured in terms of habitat loss.

Question 9.
Name the hotspots present in the Indian territory?
Answer:
There are four hotspots in India.

1. East Himalaya : India’s Hotspot -1
2. Indo-Burma : India’s Hotspot -2
3. Western Ghats and Sri lanka : India’s Hotspot -3
4. Sundaland : India’s Hotspot -4

Question 10.
Write about the causes of destruction of biodiversity?
Answer:
Causes of destruction of biodiversity :
The biodiversity is threatened all over the world. Acid rain, pollution, urban development and agriculture are present everywhere. The expanding human populations destroy the habitat. It is the main threats to biological diversity.

Humans are exploiting about 40% net primary production on the earth. They convert the natural areas into agricultural land. They destroy the native species. The loss of habitat destroys thousands of native plants and animals.

Long Answer Type Questions : 5 Marks

Question 1.
How is the preservation of wildlife important for human progress?
Answer:

1. Economic value : Provide diverse variety of food materials.
2. In argiculature : Wildlife provides variations. Using these in breeding programmes man has been able to produce high yielding and disease resistant varieties of crop plants.
3. In animal husbandry and fishery : Breeding of high yielding disease and stres resistance breeds of animals and better quality fishes has been possible by introduction and hybridization.
4. In modern medicine and surgery : Selection and development of strains of anibiotic producing microoganisms. Identification of medicines and drug producing plants like Cinchona and Rauwolfia.
5. Development of biofertilizers : Use of Nostoc, Anabaena and Azospirllium has been possible as a result of study of naturally growing microorganisms.
6. Biological control of pests and pathogens: Cactoblatis cactorum used to control growth of cacti in Australia, has been possible through identification of wildly occuring insects.

Question 2.
What are the needs for conservation?
Answer:

1. Maintenance of balance of nature
2. Economic value
3. Scientific value
4. Aesthetic value – enjoyment of the beauty of nature
5. Culural value
6. Protection of our civilization
7. Evolutionary responsibility

Question 3.
What are the strategies for conservation of wildlife?
Answer:
i. Forest fires-natural and man-made

ii. Hunting as sport e.g. disappearance of Dodo a unique bird of Mauritius and Cheetah from India.

iii. Deforestation and habitat destruction: Due to the conversion of habitat of wildlife for human settlement, crop lands, grazing grounds, plantation, mining, dams reservoirs, harbours.

iv. Introduction of exotic species: Causes competition, predation, habitat destruction, transmission of diseases, e.g. introduction of goats and rabbits in the Islands of Pacific and Indian Ocean have destroyed habitats of plants, birds and reptiles.

v. Over-exploitation of natural resources: Killing of animals for hides and skin, meat and flesh, aphrodisiacs and decoration pieces. Collection of rare plants of wild origin for pharmaceuticals, perfumes, cosmetics and for museum collections. Students inadvertently destroy rare plants and insects during excursions for collections.

Question 4.
Write the importances of biodiversity?
Answer:
Importance of the following biodiversity :

1. Forests hold back flood waters and recycle CO₂ and nutrients.
2. Insects pollinate crops and control insect pests.
3. The subterranean organisms promote soil fertility through decomposition.
4. Many of these undescribed species will provide new food crops, petroleum substitutes, new fibres and pharmaceuticals. All of these functions require large healthy populations.
5. Large populalions promote the genetic diversity.

This diversity is required for the survival of the species in the changing environment. The genetic diversity is lost forever. The zoologists are trying to save endangered species. But they are able to save only a tiny portion of genetic pool.

Question 5.
What are the causes for the extinction of wildlife?
Answer:
Causes for the extinction of wildlife :
Natural calamities : Many species of wildlife have become depleted or extinct because of natural calamities, such as earthquakes, floods, droughts, fire and epidemics.
Depriving of natural habitat: A major cause of the extinction of wildlife is human activity. Conversion of vast areas of grasslands and forests into agricultural lands have deprived wildlife of their natural habitats.

Deforestation : Wherever civilization advances, forests are destroyed. Forests were cleared to obtain building material, fuel or land for agriculture.

Hunting : Hunting for sport or for animal products led to large scale endangerment and extinction of many species of animals. Tigers and leopards were killed for their skins, rhinoceros for their horns, elephants for their tusks, musk deer for the perfumed pods under their bellies, black bears for their gall bladder, alligators for their skin used in the making of fancy luggage and shoes and snakes for making belts and purses. Fantastic price are obtained in the underground markets.

Question 6.
Write about in situ conservation.
Answer:
In situ conservation : It is conservation and protection of the whole ecosystem and its biodiversity at all levels in order to protect the threatened species. Two alternate methods are being used to save biodiverstiy, hotspots and protected areas.
Hotspots : They are areas with high density of biodiversity or mega diversity which are also the most threatened ones. Ecologically hotspots are determined by four factors.

• Number of species/species diversity.
• Degree of endemism.
• Degree of threat to habitat due to its degradation and fragmentation.
• Degree of exploitation.

Myers (1988) initially identified 12 hotspots with 14% of plant species in an area of only 0.2%. Four more hotspots were added by Myers (1991). Today the number of hotspots identified by ecologists is 34 , covering an area less than 2% of land surface with about 20% of human population living there. India has three hotspots Indo-Burma, Himalayas and Western Ghats – Sri Lanka. India is even otherwise a country of mega diversity with 2.4% of land area and having 8.1% ‘of global diversity. Major centres of biodiversity are Agasthyamalai hills, Silent valley and Amambalam reserve. There is high degree of endemism as well as richness of species of flowering plants, amphibians, reptiles, some mammals and butterflies. Indo-Burma hotspot extends from Bhutan to Myanmar covering most of north-east. Valleys of this region are rich in endemic species, it has been an active centre of evolution of flowering plants, being rich in primitive angiosperm genera (e.g., Magnolia, Betula) and primitive angiosperm families (e.g., magnoliaceae, winteraceae).

Protected areas : They are ecological/biogeographical areas where biological diversity along with natural and cultural resources is protected, maintained and managed through legal or other effective measures. They are delimited on the basis of biological diversity, e.g. cold desert (Ladakh and Spiti), hot desert (Thar), wetland (Assam), saline swampy area (Sundarbans) etc. Protected areas include national parks, sanctuaries and biosphere reserves.

National parks: They are areas maintained by government and reserved for betterment of wildlife. Cultivation, grazing, forestry and habitat manipulation are not allowed.

Sanctuaries : They are tracts of land with or without lake where wild animals/ fauna can take refuge without being hunted. Other activities like collection of forest products, harvesting of timber, private ownership of land, tilling of land etc. are allowed. India has 448 wildlife sanctuaries.

Biosphere reserves : They are multipurpose protected areas which are meant for preserving genetic diversity in representative ecosystems of various natural biomes and unique biological communities by protecting wild populations, traditional life style of tribals and domesticated plant/animal genetic resources. Creation of biosphere reserve was initiated in 1975 under MAB programme of UNESCO. Till May 2002,408 biosphere reserves had been established in 94 countries. In India, 14 potential sites were identified in 1979 by Core Advisory Group. They are also notified as national parks. Each biosphere reserve has

Core or Natural Zone : No human activity is allowed. The area is undisturbed and has legally protected ecosystem.

Buffer Zone : It surrounds the core area. Limited human activity is allowed like resource use strategies, research and education.

Transition Zone (Manipulation Zone) : It is the outermost or peripheral part of biosphere reserve where an active cooperation is present between reserve management and local people for activities like settlements, cropping, recreation, forestry and other economic uses without disturbing ecology. Transition zone has different parts like forestry, agriculture, tourism and restoration regions. Restoration region is degraded area which is selected for restoration to near natural form.

Importance of biosphere reserves includes :

1. Restoration – Biosphere reserves help in restoration of degraded ecosystems and habitats.
2. Conservation – They are means of conserving genetic resources, species, ecosystems and landscapes without uprooting the local people.
3. Development – They ensure culturally, socially and ecologically sustainable economic development.
4. Monitoring – There is a regular monitoring of development and conservation progress.
5. Education and research – Each biosphere reserve supports education of information about research, restoration, conservation and development aspects at the national and global levels.

Sacred forests and lakes – Sacred forests (= sacred groves) are forest patches around places of worship which are held in high esteem by tribal communities. They are the most undisturbed forest patches (island of pristine forests), which are often surrounded by highly degraded landscapes. They are found in several parts of India, e.g.- Karnataka, Maharashtra, Rajasthan. Not a single branch is allowed to be cut from these forests. As a result many endemic species which are rare or have become extinct elsewhere can be seen to flourish here.

Question 7.
Write about ex situ conservation :
Answer:
Ex situ conservation : It is conservation of threatened plants/animals in places outside their natural homes. Ex situ conservation includes offsite collections and gene banks. The two are also a source of genetic material for breeders and genetic engineers.

Offsite collections : They are live collections of wild and domesticated species in botanical gardens, zoological parks, wildlife safari parks, arboreta (approx arboretums = arboretums) etc. Currently, there are more than 1500 botanical gardens and arboreta (gardens with trees and shrubs) having more than 80,000 species. Many of them have seed banks, tissue culture facilities and other in situ technologies.The number of zoos/ zoological parks is more than 800 . They have about 3000 species of mammals, birds, reptiles and amphibians. Most of them have well managed captive breeding programmes. As a result many animals which have become extinct in the wild continue to be maintained in zoological parks.

Gene banks : They are institutes that maintain stocks of viable seeds (seed banks), live growing plants (orchards), tissue culture and frozen germplasm with the whole range of genetic variability.

Seed banks : Seeds are of two types, orthodox and recalcitrant. Orthodox seeds are those seeds which can tolerate reduction in moisture content (upto 5%), anaerobic conditions and low temperature of -10° to -20°C or even lower for prolonged periods, e.g. cereals, legumes. At intervals the seeds are allowed to germinate, form plants and develop fresh seeds for storage. Recalcitrant seeds are those seeds which get killed on reduction of moisture and exposure to low temperature, e.g., tea, cocoa, jackfruit, coconut. They can be stored for shorter duration after treatment with fungicides in rooms having humid air and normal oxygen.

Orchards : Plants with recalcitrant seeds are grown in orchards where all possible strains and varieties are maintained, e.g. litchi, oil palm, rubber tree etc. .

Tissue culture – It is carried out through callus formation, embryoids, pollen grain culture and shoot tip culture for those plants which are either seedless, have recalcitrant seeds, variable seed progeny or where clone is to be maintained. The method is useful in maintaining a large number of genotypes in small area, rapid multiplication of even endangered species and for hybrid rescue. Shoot tip culture maintains virus free plants. It is used for international exchange of germplasm in vegetatively multiplied cultivars, e.g., banana, potato.

Cryopreservation : Preservation at -196°C (liquid nitrogen) can maintain tissue culture, embryos, animal cells/tissues, spermatozoa indefinitely. The cryopreserved material is revived through special technique when required.

Question 8.
Give a list of some important wild animal on india.
Answer:

Question 9.
List some National Parks of India
Answer:

Question 10.
Compare National park, sanctuary and biosphere reserve.
Answer:

National park	Sanctuary	Biosphere reserve
1. Hitched to the habitat for particular wild animal species like tiger, lion, angul, rhino etc.	Generally species-oriented as Citrus, pitcher plant, Great Indian Bustard.	Not hitched to anyone, two or more species, but to the whole ecosystem i.e. totality of all forms of life i.e., ecosystem oriented.
2. India, the size range is 0.04 to 3162 sq. km. Most common (in about 40%) is 100 to 500. km. In 15% is 500 to 1000sq. km.	Size range.is 0.61 to 7818 sq. km. Most common (in about 40%) is 100 to 500 sq. km. In 25% is 500 to 1000 sq. km.	Size range over 5670 sq. km.
3. Boundaries circumscribed by legislation.	Boundries not sacrosanct.	Boundaries circumscribed by legislation.
4. Except the buffer zone, no biotic interference.	Limited biotic interference.	Except of buffer zone, no biotic interference.
5. Tourism permissible.	Tourism permissible.	Tourism normally not permissible
6. Research and scientific management lacking	Lacking	Managed
7. So far no attention to genepools and conservation.	So far no attention.	Attention given

Question 11.
Give a list of some important sanctuaries in India.
Answer:

Name, location and area (in sq. km.)	Important animals found
1. Annamalai Sanctuary, Coimbatore (Tamil Nadu), 958	Elephant, tiger, panther, gaur, sambhar, spotted deer, sloth bear, wild dog, barking deer.
2. Jaldapara Sanctuary, Madarihat (West Bengal), 1,155	Rhino, elephant, tiger, leopard, gaur, deer, sambhar, different kinds of birds.
3. Keoladeo Ghana Bird Sanctuary, Bharatpur (Rajastnan) (Earlier it was once the duck shooting ground of a king), 29	Siberian crane, storks, egrets, herons, spoon bill etc. Drier parts of this marshy sanctuary have spotted deer, black buck, sambhar, wild boar, blue bull, python. This sanctuary is famous for aquatic birds.
4. Sultanpur Lake Bird Sanctuary, Gurgaon (Haryana), 12	Crane, sarus, spotbill, duck, drake, green pigeon, wild boar, crocodile, python.
5. Bir Moti Bagh Wildlife Sanctuary, Patiala (Punjab), 8.3 Mandi (Himachal Pradesh), 213	Nilgai, wild boar, hog deer, black buck, blue bull, jackal, peafowl, partridge, sparrow, myna, pigeon, dove.
6. Shikari Devi Sanctuary,	Black bear, snow leopard, flying fox, barking deer, musk deer, chakor, partridge.
7. Dachigam Sanctuary Srinagar, (Jammu and Kashmir), 89	Hangul or Kashmiri stag, musk deer, snow leopard, black bear, brown bear.
8. Mudumalai 11. wildlife Sanctuary Nilgiri (Tamil Nadu), 520	Elephant, gaur, sambhar, chital, barking deer, mouse deer, four homed antelope, langur, giant squirrel, flying squirrel, wild dog, wild cat, civet, sloth bear, porcupine, python, rat, snake, monitor lizard, flying lizard.
9. Nagarjuna Sagar Sanctuary Guntur, Kamool and Nalgonda (Andhra Pradesh), 3, 568 km	Tiger, panther, wild boar, chital, nilgai, sambhar, black buck, fox, jackal, wolf, crocodile.
10. Periyar Sanctuary, Idduki (Kerala), 777 km	Elephants, gaur, leopard, sloth bear, sambhar, bison, black · langur, hornbill, egret. It is famous for elephants.
11. Chilka Lake Bird Sanctuary, Balagaon (Odisha) (Largest brackish water lagoon in Asia), 900 km	An oasis of birds like water fowls ducks, crane’s, golden plovers, sand pipers, flamingoes.
12. Manas Wildlife Sanctuary, Kamrup (Assam)	Tiger, panther, rhino, gaur, wild buffalo, sambhar, swamp deer, golden Tangur, wild dog, wild boar.

Question 12.
Make a list of some Biosphere reserves in India.
Answer:

Biosphere Reserve	State
1. Nilgiri (First biosphere reserve established in India (1986)]	Karrnnataka
2. Nanda Devi(1988)	Uttaranchal
3. Gulf of Mannar	Tamil Nadu
4. Agasthyamalai	Kerela.
5. Sundarbans	West Bengal
6. Panchmari	M.P
7. Manas	Assam
8. Kanchenjunga	Sikkim
9. Nokrek (Tura range)	Meghalaya
10. Great Nicobar	Andaman and Nicobar
11. Similipal	Odisha
12. Dibru Saikhowa	Assam
13. Dehang Debang	Arunachal Pradesh
14. Achanakmar – Amarkantak	Chhattisgarh

Question 13.
State the environmental problems of Sundarban.
Answer:
The threats to the mangrove eco-system are arising partly due to biotic pressure from the surrounding environment and partly due to human induced or natural changes in the upper catchments. These can be outlined as below

• Reduced flow of sweet water into Sundarban mangrove system
• Extension of non-forestry land use into mangrove forest
• Straying of tiger into villages along the western boundary of Sundarban
• Demand for small timber and fuel wood for local consumption
• Poaching of tiger, spotted deer, wild boar, marine turtles, horse shoe crab etc
• Uncontrolled collection of prawn seedlings
• Uncontrolled fishing in the water of reserve forests
• Continuous trampling of river/creek banks by fishermen and prawn seed collectors
• Chemical pollution through marine paints and hydrocarbons
• Long international border along the Eastern boundary of Indian Sundarban
• Organizational and infrastructure deficiencies

Question 14.
What do you mean by JFM?
Answer:
Joint Forest Management often abbreviated as JFM is the official and popular term in India for partnerships in forest movement involving both the state-forest departments and local communities. The policies and objectives of Joint Forest Movement are detailed in the Indian comprehensive National Forest Policy of 1988 and the Joint Forest Movement Guidelines of 1990 of the Government of India.

Although schemes vary from state to state and are known by different names in different Indian languages. Usually a village committee known as the Forest Protection Committee (FPC) and the Forest Department enter into a JFM agreement. Villagers agree to assist in the safeguarding of forest resources through protection from fire, grazing, and illegal harvesting in exchange for which they receive non-timber forest products and a share of the revenue from the sale of timber products.

Question 15.
What do you mean by PBR?
Answer:
People’s Biodiversity Register (PBR) : One of the mandates of the biodiversity board is to prepare biodiversity registers for each LSG involving the local communities. Biodiversity registers are being prepared with the help of the local people and hence referred as People’s Biodiversity Register (PBR).
Preparation of biodiversity register is an attempt to realize the biodiversity at

local self government level, states and the whole country. Identification of biological resources and documentation is one of the prerequisites for the Register preparation which can lead to new discoveries and development of new commercial products, patenting of such products, equitable distribution of benefits, if any, and through this paving the way for a new economic order in the country through biodiversity conservation.

PBR is not simply a register with names of species and their distribution in a given area. It is a comprehensive data base recording people’s traditional knowledge and insight of the status, uses, history, ongoing changes and forces driving these changes on the biological diversity resources of their own localities. This will also provide information on the current utilization patterns of biodiversity, its economic benefits to the local communities. The registers form a baseline data for future management strategies required for the sustainable utilization of biodiversity in a decentralized manner. Further, it helps equitable sharing of benefits arising out of commercial utilization of biodiversity resources and knowledge on their uses. The biodiversity register offers conservation, protection of IPR and the traditional knowledge.

Multiple Choice Questions : 1 Mark

Question 1.
Rare endangered and endemic taxa can be found intact and flourishing in
(a) sacred groves
(b) tropical forest
(c) oases
(d) buffer zone of biosphere reserve.
Answer:
(a) sacred groves

Question 2.
Antilope cervicapra/Black Buck is
(a) vulnerable
(b) endangered
(c) critically endangered
(d) extinct in the wild.
Answer:
(a) vulnerable

Question 3.
Susceptibility to extinction is due to
(a) large body size
(b) small population
(c) high trophic level
(d) all of these
Answer:
(d) all of these

Question 4.
World Conservation Union maintains
(a) red data book
(b) red list
(c) pink list
(d) both (a) and (b)
Answer:
(d) both (a) and (b)

Question 5.
Keoladeo Ghana National Park is situated in
(a) Bihar
(b) Rajasthan
(c) Uttar Pradesh
(d) West Bengal
Answer:
(b) Rajasthan

Question 6.
First biosphere reserve was established in 1986 at
(a) Nilgiri
(b) Nanda Devi
(c) Rann of Kutch
(d) Sundarbans
Answer:
(a) Nilgiri

Question 7.
Nanda Devi Biosphere Reserve is found in
(a) Uttaranchal
(b) Assam
(c) Himachal Pardesh
(d) Andhra Pardesh.
Answer:
(a) Uttaranchal

Question 8.
Symbol of WWF is
(a) Tiger
(b) Rhododendron
(c) White bear
(d) Giant panda.
Answer:
(d) Giant panda.

Question 9.
National Forest Policy was enunciated in
(a) 1972
(b) 1978
(c) 1982
(d) 1988
Answer:
(d) 1988

Question 10.
Social Forestry Programme was started in
(a) 1970
(b) 1976
(c) 1968
(d) 1985
Answer:
(b) 1976

Question 11.
Forest destruction results in
(a) loss of wild life
(b) floods and drought
(c) soil erosion
(d) all of these
Answer:
(d) all of these

Question 12.
Tiger is not a resident in which one of the following National park?
(a) Sundarbans
(b) Gir
(c) Jim Corbett
(d) Ranthambhor
Answer:
(b) Gir

Question 13.
Chipko movement was launched for the protection of
(a) forests
(b) livestock
(c) wetlands
(d) grasslands
Answer:
(a) forests

Question 14.
Which one of the following is a pair of endangered species?
(a) Garden lizard and Mexican poppy
(b) rhesus monkey and sal tree
(c) Indian peacock and carrot grass
(d) hornbill and Indian aconite
Answer:
(d) hornbill and Indian aconite

Question 15.
If the Bengal tiger becomes extinct
(a) hyenas and wolves will become scarce
(b) the wild areas will be safe for man and domestic animals
(c) its gene pool will be lost for ever
(d) the populations of beautiful animals like deers will get stabilized.
Answer:
(d) the populations of beautiful animals like deers will get stabilized.

Question 16.
One of the ex situ conservation methods for endangered species is
(a) wildlife sanctuaries
(b) biosphere reserves
(c) cryopreservation
(d) national parks
Answer:
(c) cryopreservation

Question 17.
Biosphere reserves differ from national parks and wildlife sanctuaries because in the former
(a) human beings are not allowed to enter
(b) people are an integral part of the system
(c) plants are paid greater attention than the animals
(d) living organisms are brought from all over the world and preserved for posterity
Answer:
(b) people are an integral part of the system

Question 18.
Red Data Book is concerned with
(a) red pigmentation of plants
(b) red algae
(c) endangered species
(d) exotic species
Answer:
(c) endangered species

Question 19.
The chipko movement for conservation of forests was started in 1972 in
(a) North Kanara district
(b) Silent Valley
(c) Sundarbans
(d) Tehri-Garhwal
Answer:
(d) Tehri-Garhwal

Question 20.
Which of the following plant is an endangered species in India?
(a) Lycopodium sp.
(b) Pinus roxburghii
(c) Hydrua
(d) Cedrus deodara.
Answer:
(a) Lycopodium sp.

Question 21.
Under the umbrella of social forestry a system has been launched in which agriculture and forestry are involved. Select the name of the system
(a) block cutting system
(b) jhum cultivation system
(c) taungya system
(d) none of these
Answer:
(c) taungya system

Question 22.
Which of the following birds is on the verge of extinction in India?
(a) Peacock
(b) Pintail ducks
(c) Hornbill
(d) Great Indian Bustard
Answer:
(d) Great Indian Bustard

Question 23.
Germplasm conservation at liquid N₂ temperature is
(a) stratification
(b) cryopreservation
(c) scarification
(d) none of these
Answer:
(b) cryopreservation

Question 24.
Which one of the following the first national park in India?
(a) Kanha national park
(b) Periyar national park
(c) Corbett national park
(d) Bandipur national park
Answer:
(a) Kanha national park

Question 25.
Deforestation causes
(a) water pollution
(b) soil erosion
(c) noise pollution
(d) soil pollution
Answer:
(b) soil erosion

Question 26.
Which national park is the new home of the Indian one-horned rhinoceros ?
(a) Dudhwa
(b) Corbett
(c) Kanha
(d) Bandhavgarh
Answer:
(a) Dudhwa

Question 27.
Which was the first national park established in India?
(a) Kanha
(b) Jim corbett
(c) Kaziranga
(d) Gir
Answer:
(a) Kanha

Question 28.
List of endangered species was released by
(a) IUCN
(b) BBC
(c) WCC
(d) UN
Answer:
(a) IUCN

Question 29.
A threatened species category included
(a) only endangered species
(b) only vulnerable species
(c) endangered and rare species
(d) endangered, vulnerable and rare species
Answer:
(d) endangered, vulnerable and rare species

Question 30.
and are combination of Agroforestry
(a) Fodder crops, fibre crop
(b) Food crops, fibre crop
(c) Trees, grasses
(d) Food crops, tree crop
Answer:
(d) Food crops, tree crop

Question 31.
A non-renewal source of energy is
(a) Wild life
(b) Fossil fuels
(c) Water
(d) Forest
Answer:
(b) Fossil fuels

Question 32.
A plant endemic to India is
(a) Banyan
(b) Ginkgo
(c) Sequoia
(d) Triticum
Answer:
(a) Banyan

Question 33.
A recent technique for the study of vegetation is
(a) Ground photography
(b) Remote sensing
(c) Field work
(d) Observation
Answer:
(b) Remote sensing

Question 34.
A renewable exhaustible natural resource is
(a) Forest
(b) Coal
(c) Petroleum
(d) Minerals
Answer:
(a) Forest

Question 35.
A species restricted to a given area is
(a) Endemic species
(b) Allopatric species
(c) Sympatric species
(d) Sibling species
Answer:
(a) Endemic species

Question 36.
According to IUCN red list, what is the status of Red Panda (Ailurus fulgens)
(a) Critically endangered
(b) Endangered species
(c) Vulnerable species
(d) Extinct species
Answer:
(b) Endangered species

Question 37.
Agroforestry and social forestry both include
(a) Production forestry
(b) Commercial forestry
(c) Afforestation
(d) Plantation of trees
Answer:
(d) Plantation of trees

Question 38.
An endangered bird is
(a) Passenger Pigeon
(b) Pink-headed duck
(c) Great Indian Bustard
(d) Vulture
Answer:
(c) Great Indian Bustard

Question 39.
An endangered species from the following
(a) Azardirachta
(b) Rosa indica
(c) Rauvolfia serpentina
(d) Acacia arabica
Answer:
(c) Rauvolfia serpentina

Question 40.
An example of ex-situ conservation is
(a) Seed bank
(b) Sacred groves
(c) National parks
(d) Wildlife sanctuary
Answer:
(a) Seed bank

Question 41.
An exhaustible renewable resource is
(a) Coal
(b) Solar energy
(c) Fresh water
(d) Petroleum
Answer:
(c) Fresh water

Question 42.
An inexhaustible and renewable source of energy is
(a) Wood
(b) Natural gas
(c) Fossil fuel
(d) Hydropower
Answer:
(d) Hydropower

Question 43.
Antíropogenic extinction occurs due to
(a) Earthquakes
(b) Floods
(c) Changing environmental conditions
(d) Human activities
Answer:
(d) Human activities

Question 44.
Biogas is which type of natural resources
(a) Renewable
(b) Inexhaustible
(c) Non-conventional
(d) Both(a) and(c)
Answer:
(a) Renewable

Question 45.
Chipko Movement is an example of forest conservation through
(a) Tehri-Garhwal district
(b) Uttaranchal
(c) Public awareness and participation
(d) Political issue
Answer:
(c) Public awareness and participation

Question 46.
Chipko movement is related to
(a) Forest conservation
(b) Soil conservation
(c) Water conservation
(d) Wetland conservation
Answer:
(a) Forest conservation

Question 47.
Chipko movement was launched for protection of
(a) Forests
(b) Grasslands
(c) Wetlands
(d) Livestocks
Answer:
(a) Forests

Question 48.
Conservation of species in its natural habitat is
(a) In-situ
(b) Ex-situ
(c) In-vitro
(d) Both(b) and(c)
Answer:
(a) In-situ

Question 49.
Deforestation brings about
(a) Soil erosion
(b) Weed control
(c) Decreased drought
(d) Increased sunlight
Answer:
(a) Soil erosion

Question 50.
Deforestation is caused due to
(a) Silviculture
(b) Construction of roads
(c) Rainfall
(d) Plantation of trees
Answer:
(b) Construction of roads

Question 51.
Deforestation is the major causal agent of
(a) Depletion of natural resources
(b) Environmental pollution
(c) Desertification of habitat
(d) Genetic erosion
Answer:
(c) Desertification of habitat

Question 52.
Deforestation will decrease
(a) Soil erosion
(b) Land slides
(c) Soil fertility
(d) Rainfall
Answer:
(d) Rainfall

Question 53.
Development of botanical garden is what type of conservation
(a) Ex-situ
(b) A common
(c) An easy
(d) In-situ
Answer:
(a) Ex-situ

Question 54.
Ex-situ conservation is carried out in
(a) Sanctuary
(b) National park
(c) Biosphere reserve
(d) Zoo
Answer:
(d) Zoo

Question 55.
Extensive planting of trees to increase forest cover is called
(a) Deforestation
(b) Agroforestry
(c) Social forestry
(d) Afforestation
Answer:
(d) Afforestation

Question 56.
For mapping, Remote sensing equipment is mounted on
(a) Aircraft and satellite
(b) Ship and spacecraft
(c) Satellite and spacecraft
(d) All of these
Answer:
(a) Aircraft and satellite

Question 57.
Forests control drought by
(a) Preventing soil erosion
(b) Increasing oxygen
(c) Increasing humidity and rainfall
(d) Preventing floods
Answer:
(c) Increasing humidity and rainfall

Question 58.
Fresh water present on earth is
(a) 97.5%
(b) 0.01%
(c) 2.5%
(d) 1.97%
Answer:
(c) 2.5%

Question 59.
Fresh water problem arises due to
(a) Globally available stocks are insufficient
(b) Uneven distribution on earth
(c) No regeneration of required quantity through natural hydrological cycle
(d) Anyone of the above
Answer:
(d) Anyone of the above

Question 60.
Gamma and X-rays are not used for remote sensing because
(a) They are absorbed by object
(b) They are reflected by object
(c) They are absorbed by layer of atmosphere
(d) They are not absorbed
Answer:
(c) They are absorbed by layer of atmosphere

Question 61.
Geo-stationary satellites
(a) Rotate very fast
(b) Are located near the earth
(c) Are stationary
(d) Rotate with speed equal to that of earth
Answer:
(d) Rotate with speed equal to that of earth

Question 62.
Human dominated biosphere is called
(a) Troposphere
(b) Stratosphere
(c) Hemisphere
(d) Noosphere
Answer:
(d) Noosphere

Question 63.
In a National Park protection is provided to
(a) Entire ecosystem
(b) Flora and fauna
(c) Fauna only
(d) Flora only
Answer:
(b) Flora and fauna

Question 64.
In India, common type of forest is
(a) Tropical thorn forests
(b) Sal and Teak forests
(c) Tropical moist deciduous forest
(d) Tropical dry deciduous forest
Answer:
(d) Tropical dry deciduous forest

Question 65.
Inexhaustible resource among the following is
(a) Minerals
(b) Solar energy
(c) Plants
(d) Fossil fuels
Answer:
(b) Solar energy

Question 66.
INSAT system is type of
(a) Satellite
(b) Geo-stationary satellite
(c) Sun-synchronous satellite
(d) Orbital satellite
Answer:
(b) Geo-stationary satellite

Question 67.
Islands have higher number of endemic species as they are separated from land masses by
(a) Deserts
(b) Mountains
(c) Large expanses of water
(d) Valleys
Answer:
(c) Large expanses of water

Question 68.
It is not a protected forest
(a) Reserve forest
(b) Sanctuary
(c) Core of biosphere
(d) Orchard
Answer:
(d) Orchard

Question 69.
IUCN stands for
(a) Indian Union of chemical Nomenclature
(b) Indian Union of Conservation of Nature
(c) International Union for Conservation of Nature
(d) International Union for Conservation of Nutrients
Answer:
(c) International Union for Conservation of Nature

Question 70.
Life supporting zone of earth’s surface is
(a) Lithosphere
(b) Biosphere
(c) Stratospere
(d) Ecotene
Answer:
(b) Biosphere

Question 71.
Main cause of extinction of species from tropical areas is
(a) Afforestation
(b) Deforestation
(c) Pollution
(d) Soil erosion
Answer:
(b) Deforestation

Question 72.
Main source of water to soil is
(a) Rainfall
(b) River
(c) Canals
(d) Lakes
Answer:
(a) Rainfall

Question 73.
Maximum use of fresh water is in
(a) Agriculture
(b) Domestic use
(c) Industry
(d) Pisciculture
Answer:
(a) Agriculture

Question 74.
More than 70% of world’s fresh water is contained in
(a) Ponds
(b) Glaciers and polar ice caps
(c) Green land
(d) Oceans
Answer:
(b) Glaciers and polar ice caps

Question 75.
Most effective controlling flood is
(a) Deforstation
(b) Constructing dams
(c) Reforestation
(d) Dagging canal
Answer:
(c) Reforestation

Question 76.
Most of the endangered species are victims of
(a) Acid rain
(b) Competition with exotic species
(c) Over hunting
(d) Habitat Destruction
Answer:
(d) Habitat Destruction

Question 77.
Natural resource which have definite cycle is
(a) Exhaustible Non-renewable
(b) Inexhaustible
(c) Non conventional
(d) Exhaustible Renewable
Answer:
(d) Exhaustible Renewable

Question 78.
Natures hydrogical cycle involves
(a) Evaporation, condensation
(c) Evaporation, precipitation
(b) Condensation, precipitation
(d) Evaporation, condensation and precipitation
Answer:
(d) Evaporation, condensation and precipitation

Question 79.
Out of total amount of water, the water found in seas and oceans is about
(a) 70%
(b) 90%
(c) 97%
(d) 85%
Answer:
(c) 97%

Question 80.
Planned management of natural resources is
(a) Not possible
(b) Not easy
(c) called conservation
(d) Called depletion
Answer:
(c) called conservation

Question 81.
Plantation of trees along with monocot crops is known
(a) Agroforestry
(b) Silviculture
(c) Social forestry
(d) Afforestation
Answer:
(a) Agroforestry

Question 82.
Planting of trees on unused farm land, rail and road sides etc. is called
(a) Commercial forestry
(b) Agroforestry
(c) Social forestry
(d) Reforestation
Answer:
(a) Commercial forestry

Question 83.
Planting of trees, shrub sand others in between crop plants for commercial exploitation and stabilization of soil is
(a) Taungya system
(b) Social forestry
(c) Agroforestry
(d) Production plantation
Answer:
(c) Agroforestry

Question 84.
Plants of endangered species are conserved through
(a) Herbarium
(b) Gene library
(c) Gene bank
(d) Reducting pollution
Answer:
(c) Gene bank

Question 85.
Population of species decreasing over a period called as
(a) Extinct
(b) Eliminated
(c) Endangered
(d) Rare
Answer:
(c) Endangered

Question 86.
Radiations not useful in remote sensing are
(a) UV radiations
(b) Microwave
(c) Ultrasonic waves
(d) Infra-red radiations
Answer:
(c) Ultrasonic waves

Question 87.
Red Data Book contains information about
(a) Red coloured insects
(b) Red eyed bird
(c) Red coloured fishes
(d) Endangered plants and animals
Answer:
(d) Endangered plants and animals

Question 88.
Red Data Book deals with
(a) Maintains and publish list of endangered and endemic species
(b) Maintains and publish list of Plants that are extinct
(c) Maintains and publish list off Animals that are extinct
(d) Maintains and publish list of dangerous species
Answer:
(a) Maintains and publish list of endangered and endemic species

Question 89.
Reforestation is
(a) Plantation of forests
(b) Plantation forests in deforested areas
(c) Cutting down of forests
(d) Management of forests
Answer:
(b) Plantation forests in deforested areas

Question 90.
Remote sensing involves the use of
(a) EMR
(b) NMR
(c) ESR
(d) SSR
Answer:
(a) EMR

Question 91.
Resources which are available in unlimited quantity are
(a) National resources
(b) Exhaustible resources
(c) Inexhaustible resources
(d) Natural resources.
Answer:
(c) Inexhaustible resources

Question 92.
Serious threat to wild life is
(a) Habitat destruction
(b) International trade
(c) Introduction of exotic species
(d) Over-exploitation
Answer:
(a) Habitat destruction

Question 93.
Shifting cultivation is also known as
(a) Taungya system
(b) Shum cultivation
(c) Social forestry
(d) Plant cultivation
Answer:
(b) Shum cultivation

Question 94.
Solar energy is which type of natural resources
(a) Renewable
(b) Non-renewable
(c) Exhaustible
(d) Inexhaustible
Answer:
(d) Inexhaustible

Question 95.
Taungya is practice of
(a) Shifting cultivation
(b) Agroforestry
(c) Production forestry
(d) Both A and B
Answer:
(d) Both A and B

Question 96.
The base on which remote sensors are mounted is termed as
(a) Camera
(b) Energy source
(c) Platform
(d) Scanner
Answer:
(c) Platform

Question 97.
The endangered fauna is
(a) The Great Indian Bustard
(b) Viviparous toad
(c) Forest owl
(d) Kashmiri stag
Answer:
(a) The Great Indian Bustard

Question 98.
The function of tree plantation is celebrated through
(a) Environment day
(b) Vanikaran
(c) Social forestry programme
(d) Vasant Mahotsav
Answer:
(c) Social forestry programme

Question 99.
The human activities resulting in endangered species are
(a) Poaching
(b) Deforestation
(c) Forest fires
(d) All of these
Answer:
(d) All of these

Question 100.
The life supporting gases such as O₂, CO₂ and N₂ are primarily concentrated in
(a) troposphere
(b) exosphere
(c) homosphere
(d) stratosphere
Answer:
(a) troposphere

Question 101.
The main reserve of fresh water on earth surface is
(a) Ground water
(b) Rivers
(c) Lakes
(d) Polar ice caps and glaciers
Answer:
(d) Polar ice caps and glaciers

Question 102.
The management of resources on earth which maintains the balance between human requirements and other species is
(a) Conservation
(b) Industrialization
(c) Diversity of ecosystem
(d) Geological diversity
Answer:
(a) Conservation

Question 103.
The natural cause for extinction of species is
(a) Floods
(b) Hunting
(c) Industrialization
(d) Destruction of natural habitats
Answer:
(a) Floods

Question 104.
The natural resources available in limited quantity at global level is
(a) Non-renewable
(b) Renewable
(c) Exhaustible
(d) Inexhaustible
Answer:
(c) Exhaustible

Question 105.
The natural resources which are continuously consumed by man but are replenished by nature with a reasonable period of time is called
(a) Exhaustible
(b) Inexhaustible
(c) Exhaustible renewable
(d) Exhaustible non-renewable
Answer:
(c) Exhaustible renewable

Question 106.
The percentage of evaporation of water from land and ocean surface are respectively
(a) 16 and 84%
(b) 84 and 16%
(c) 65 and 35%
(d) 60 and 40%
Answer:
(a) 16 and 84%

Question 107.
The restricted distribution of species in small area called
(a) Biome
(b) Niche
(c) Endemism
(d) Ectosphere
Answer:
(c) Endemism

Question 108.
The vehicle used to carry the sensor in remote sensing is
(a) Camera
(b) Shuttle
(c) Scanner
(d) Platform
Answer:
(d) Platform

Question 109.
There is decrease in because of deforestation
(a) Soil erosion
(b) Global warming
(c) Rainfall
(d) Drought
Answer:
(c) Rainfall

Question 110.
Which has caused maximum damage to Indian forests
(a) Selective harvesting
(b) Block cutting
(c) Taungya cultivation
(d) Jhum cultivation
Answer:
(d) Jhum cultivation

Question 111.
Which of the following acts as a main source of ground water?
(a) Rain
(b) River
(c) Ocean
(d) Canals
Answer:
(a) Rain

Question 112.
Which of the following soil is the best for plant growth?
(a) Loamy soil
(b) Clay
(c) Gravel
(d) Sandy soil
Answer:
(a) Loamy soil

Question 113.
Which of the following species is endemic?
(a) Vanda
(b) Drosera sp
(c) Gnetum ula
(d) Ginkgo biloba
Answer:
(d) Ginkgo biloba

Question 114.
Which one is not an exhaustible resource
(a) Solar energy
(b) Coal
(c) Rainfall
(d) Wind power
Answer:
(b) Coal

Question 115.
Which one is not endangered species?
(a) Bald Eagle
(b) Giant Panda
(c) Podophyllum
(d) Mergosa
Answer:
(d) Mergosa

Question 116.
Which one of the following in endangered species?
(a) Cuscuta
(b) Nepenthes
(c) Datura
(d) Butea sps.
Answer:
(b) Nepenthes

Question 117.
The recent technique used for study of vegetation is
(a) Remote sensing
(b) Field works
(c) Ground photography
(d) Observation
Answer:
(a) Remote sensing

Very Short Answer Type Questions : 1 Mark

Question 1.
What is the total number of Hotspot situated in the world?
Answer:
34.

Question 2.
Who many hotspots present in India.
Answer:
4

Question 3.
Write the two causes of loss of biodiverity.
Answer:
(i) Hunting and poaching. (ii) Land use pattern.

Question 4.
Name two natural calamities due to loss of biodiversity.
Answer:
(i) Earthquakes, (ii) Tsunami.

Question 5.
Name two exotic species causing loss of biodiversity.
Answer:
Parthenium (Plant) Pesiplaneta americana.

Question 6.
Name two mangrove forests in India.
Answer:
(i) Sundarban mangrove forest.
(ii) Andaman mangrove forest.

Question 7.
How many types of conservation there are?
Answer:
Two types- (i) In-situ conservation, (ii) Ex-situ conservation.

Question 8.
Name one National Park in West Bengal.
Answer:
Jaldapara National Park.

Question 9.
Name one Sanctuary in West Bengal.
Answer:
Chapramari Sanctuary.

Question 10.
Name one Reserve forest in West Bengal.
Answer:
Bauxa Reserve forest.

Question 11.
Name one Biosphere reserve in West Bengal.
Answer:
Sundarban Biosphere reserve

Question 12.
Give two examples of ex-situ conservation.
Answer:
Zoological garden, Botanical garden.

Question 13.
What is the temperature for cryopreservation.
Answer:
-196° C

Question 14.
What is the full form of JFM
Answer:
Joint Forest Management.

Question 15.
Where and when JFM was started in India?
Answer:
Arabari forest in West Midnapur in 1971.

Question 16.
What is PBR?
Answer:
People’s Biodiversity Register.

Question 17.
Name one Tiger Project in West Bengal.
Answer:
Sundarban Tiger Project.

Question 18.
Name one Rhino Project in West Bengal.
Answer:
Jaldapara Sanctuary One-horned Rhinoceros Reserve Project.

Question 19.
Name one Lion Reserve Project.
Answer:
Lion Reserve Project in Gir Forest.

Question 20.
Name the Crocodile Reserve Project in West Bengal.
Answer:
Bhagabatpur Crocodile Reserve Project.

Question 21.
Name one Red Panda Reserve Project in West Bengal.
Answer:
Singalila National Project : Red Panda Reserve Project; Darjeeling.’

Question 22.
Which Logo is used for Red Panda conservation.
Answer:
WWF-N.

Fill in the blanks with suitable words :

1. The species of plants and animals which have disappeared from the face of the earth are said to be ___________.
2. Gene for resistance against a pest on rice, brown plant hopper (Nilaparvata lugens) was identified from old varieties of rice from ___________.
3. About ___________ plant species and ___________ vertebrate species are threatened with extinction.
4. Species of plants and animals which are in danger of becoming extinct or have become rare and are at risk are known as ___________ species.
5. Species of plants and animals which have been reduced to a critical level and are in immediate danger of becoming extinct are known as ___________ species.
6. Species of plants and animals which have been severely depleted and are likely to move into endangered category are known as ___________ species.
7. Species of plants and animals which occur in small populations restricted to localised areas or are thinly scattered over more extensive range are known as ___________ species.
8. Conservation is concerned with plants, animals, micro-organisms and their ___________.
9. The rice pest that threatened the entire rice cultivation is ___________ ___________ (Scientific name)
10. Over-fishing is depleting the ___________ living resources.
11. In the ___________ zone of biosphere reserves, no human activity is permitted.
12. In ___________ zone of bíosphere reserves, large number of human activities are allowed.
13. Only ___________ Indian Bustard birds are still living.
14. There are ___________ National Parks in our country.
15. ___________ Forestry Programme aims at planting trees for aesthetic purposes in urban settlements.
Answer:
1. extinct
2. Kerala
3. 25,000 ; 1,000
4. threatened
5. endangered
6. vulnerable
7. rare
8. environment
9. Nilaparvata lugens
10. marine
11. core
12. manipulation
13. 800
14. 66
15. Urban.

State whether the following statements are True or False. If False, then write the correct statement

Question 1.
California condor, the largest flying birds, is being affected by human cleanliness.
Answer:
True.

Question 2.
Forests play an important role in reducing atmospheric pollution.
Answer:
True.

Question 3.
Agroforestry Programme aims at reviving forests on barren agricultural land.
Answer:
False. Agroforestry Programme aims at reviving ancient practice of using same land for farming, forestry and animal husbandry.

Question 4.
The Great Indian Bustard, inhabitant of semiarid areas of Rajasthan, Gujarat and Maharashtra is considered as a rare bird.
Answer:
False. The Great Indian Bustard, inhabtant of semi-arid areas of Rajasthan, Gujarat and Maharashtra is a highly endangered bird.

Question 5.
In manipulation zone of biosphere reserve, limited human activity is allowed.
Answer:
False. In buffer zone of biosphere reserve limited human activity is allowed.

Question 6.
In a sanctuary, protection is given only to animals.
Answer:
True.

Question 7.
In-situ protection refers to the conservation of wildlife in zoos and botanical gardens.
Answer:
False. In-situ protection refers to the conservation of wildlife in their natural habited.

Question 8.
Uttarakhand Biosphere Reserve includes Silent valley in north western Himalayas.
Answer:
False. Uttarakhand Biosphere Reserve includes Valley of Flowers in northwestern Himalayas.

Question 9.
Silent valley is located in Tamil Nadu.
Answer:
False. Silent Valley is located in Kerala.

Question 10.
Tropical rain forests are the most productive forest types in the world.
Answer:
True.

Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 5C Environment and Human Population offer valuable context and analysis.

WBBSE Class 10 Life Science Chapter 5C Question Answer – Environment and Human Population

Short Answer Type Questions : 2 Marks

Question 1.
What environmental damage are caused by mercury poliution? What are the main sources of mercury pollution?
Answer:
Mercury is a metal that when present in the water of rivers, lakes and seas contaminates fish, crustaceans, molluscs and other living organisms. The mercury accumulates along the food chain and, in each following trophic level, the amount of the metal within the individuals is higher. When humans eat contaminated animals, they also become contaminated and severe nervous system injuries may result from it. The main sources of mercury pollution are gold mining and the use of substances derived from it in industry and agriculture.

Question 2.
Besides mercury, which other heavy metals cause toxic pollution?
Answer:
Examples of other heavy metals that cause toxic pollution are lead, cadmium and chromium.

Question 3.
What are persistent organic poliutants (POPs)?
Answer:
POPs, or persistent organic pollutants, are toxic substances formed from organic compounds. POPs are produced in several industrial processes, such as the production of PVC, paper whitened by chlorine, herbicides, insecticides and fungicides, as well as in the incineration of waste. Examples of POPs are dioxins, furanes, chlordane, DDT, dieldrin, heptachlor, toxaphene and hexachlorobenzene.

POPs are toxic and highly harmful since, like the heavy metals, they are bioaccumulative, meaning that they are not broken down by the body and accumulate even more in each following trophic level of the food chain. In humans, POPs can cause cancer and nervous, immune and reproductive disorders.

Question 4.
Is the upward movement of warm air good or bad for the dissipation of pollutants?
Answer:
The upward movement of warm air is a natural method of dispersing pollutants. The air near the ground is hotter because the sun heats the soil and the soil heats the air nearby. Since it is less dense, the warm air tends to move towards higher and colder strata of the atmosphere. Such movement helps to disperse pollutants.

Question 5.
Why does thermal inversion increase air pollution? What harm can thermal inversion cause to humans?
Answer:
Thermal inversion confines a layer of pollutants at low altitude, which otherwise would have been dispersed by the natural upward movement of warm air. The solid particles present in the atmosphere cause health problems, such as the exacerbation of asthma and other pulmonary diseases, coughing, respiratory unease and eye discharges. Over time, pollution can also trigger the appearance of cardiovascular and neoplastic diseases.

Question 6.
What are the health consequences of air pollution?
Answer:
Air pollution increases the risk of respiratory and heart disease in the population. Both short and long term exposure to air pollutants have been associated to health impacts. More severe impacts affect people who are already ill. Children, the elderly and poor people are more susceptible.

Question 7.
What is pathogen pollution?
Answer:
Pathogen pollution refers to the introduction of disease-causing microbes(pathogens) and/or their hosts (infected individuals) to new locations around the world. European bird species, including pigeons and the house sparrow, for example, introduced West Nile virus to the United States.

Question 8.
What is an emerging infectious disease (EID)?
Answer:
EIDs include diseases that have jumped from wildlife populations to humans, diseases that have become more frequent, and diseases that are entirely new to science. Examples of EIDs include HIV/AIDS, West Nile virus, and SARS. Lung diseases are some of the most common medical conditions in the world. Tens of millions of people suffer from lung disease in the U.S. Smoking, infections, and genetics are responsible for most lung diseases. The lungs are part of a complex apparatus, expanding and relaxing thousands of times each day to bring in oxygen and expel carbon dioxide. Lung disease can result from problems in any part of this system.

Question 9.
Write the health effect on air pollution.
Answer:
Air Pollution Effects :

1. Reduced lung functioning
2. Irritation of eyes, nose, mouth and throat
3. Asthma attacks
4. Respiratory symptoms such as coughing and wheezing
5. Increased respiratory disease such as bronchitis
6. Reduced energy levels
7. Headaches and dizziness
8. Disruption of endocrine, reproductive and immune systems
9. Neurobehavioral disorders
10. Cardiovascular problems
11. Cancer
12. Premature death.

Question 10.
Write the health effect on water pollution.
Answer:
Water Pollution Effects :

1. Waterborne diseases like typhoid,jaundice,cholera
2. Hepatitis, encephalitis, gastroenteritis, diarrhoea, vomiting, and stomach aches
3. Cancer, including prostate cancer and non-Hodgkin’s lymphoma
4. Hormonal problems that can disrupt reproductive and developmental processes
5. Damage to the nervous system
6. Liver and kidney damage
7. Damage to the DNA

Question 11.
Write the health effect on soil pollution.
Answer:
Soil Pollution Effects :

1. Lead in soil is especially hazardous for young children causing developmental damage to the brain
2. Mercury can increase the risk of kidney damage; cyclodienes can lead to liver toxicity
3. Causes neuromuscular blockage as well as depression of the central nervous system
4. Also causes headaches, nausea, fatigue, eye irritation and skin rash
5. Causes cancers including leukaemia

Long Answer Type Questions : 5 Marks

Question 1.
What do you mean by overpopulation? Write its causes.
Overpopulation
Answer:
Overpopulation is an undesirable condition where the number of existing human population exceeds the carrying capacity of Earth.Overpopulation is caused by number of factors. Reduced mortality rate, better medical facilities, depletion of precious resources are few of the causes which results in overpopulation. It is possible for a sparsely populated area to become densely populated if it is not able to sustain life.
Causes of Overpopulation
Decline in the Death Rate : At the root of overpopulation is the difference between the overall birth rate and death rate in populations. If the number of children born each year equals the number of adults that die, then the population will stabilize.

Better Medical Facilities : Following this came the industrial revolution. Technological advancement was perhaps the biggest reason why the balance has been permanently disturbed. Science was able to produce better means of producing food, which allowed families to feed more mouths.

More Hands to Overcome Poverty : For thousands of years, a very small part of the population had enough money to live in comfort. The rest faced poverty and would give birth to large families to make up for the high infant mortality rate.

Families that have been through poverty, natural disasters or are simply in need of more hands to work are a major factor for overpopulation.

Technological Advancement in Fertility Treatment : With latest technological advancement and more discoveries in medical science, it has become possible for couple who are unable to conceive to undergo fertility treatment methods and have their own babies.

Immigration : Many people prefer to move to develop countries like US, UK, Canada and Australia where best facilities are available in terms of medical, education, security and employment. The end result is that those people settle over there and those places become overcrowded.

Lack of Family Planning : Most developing nations have large number of people who are illiterate, live below the poverty line and have little or no knowledge about family planning. Getting their children married at an early age increase the chances of producing more kids.

Question 2.
Write the effects and solution of overpopulation.
Answer:
Effects of Overpopulation
Depletion of Natural Resources : The effects of overpopulation are quite severe. The first of these is the depletion of resources. The Earth can only produce a limited amount of water and food, which is falling short of the current needs. Most of the environmental damage being seen in the last fifty odd years is because of the growing number of people on the planet.

Degradation of Environment : With the overuse of coal, oil and natural gas, it has started producing some serious effects on our environment. Rise in the number of vehicles and industries have badly affected the quality of air. Rise in amount of CO₂ emissions leads to global warming. Melting of polar ice caps, changing climate patterns, rise in sea level are few of the consequences that we might we have to face due to environment pollution.

Conflicts and Wars : Overpopulation in developing countries puts a major strain on the resources, it should be utilizing for development. Conflicts over water are becoming a source of tension between countries, which could result in wars. It causes more diseases to spread and makes them harder to control. Starvation is a huge issue facing the world and the mortality rate for children is being fuelled by it. Poverty is the biggest hallmark we see when talking about overpopulation.

Rise in Unemployment : When a country becomes overpopulated, it gives rise to unemployment as there fewer jobs to support large number of people. Rise in unemployment gives rise to crime as people will steal various items to feed their family and provide them basic amenities of life.

High Cost of Living: As difference between demand and supply continues to expand due to overpopulation, it raises the prices of various commodities including food, shelter and healthcare. This means that people have to pay more to survive and feed their families.
Solutions to Overpopulation

Better Education : One of the first measures is to implement policies reflecting social change. Educating the masses helps them understand the need to have one or two children at the most. Families that are facing a hard life and choose to have four or five children should be discouraged. Family planning and efficient birth control can help in women making their own reproductive choices.

Making People Aware of Family Planning : As population of this world is growing at a rapid pace, raising awareness among people regarding family planning and letting them know about serious after effects of overpopulation can help curb population growth.

Tax Benefits or Concessions : Government of various countries might have to come with various policies related to tax exemptions to curb overpopulation. One of them might be to waive of certain part of income tax or lowering rates of income tax for those married couples who have single or two children.

Knowledge of Sex Education : Imparting sex education to young kids at elementary level should be must. Most parents feel shy in discussing such things with their kids which result in their children going out and look out for such information on internet or discuss it with their peers. Mostly, the information is incomplete which results in sexually active teenagers unaware of contraceptives and embarrassed to seek information about same. It is therefore important for parents and teachers to shed their old inhibitions and make their kids or students aware of solid sex education.

Question 3.
Describe about the Lung Diseases Affecting the Airways
Answer:
The trachea (windpipe) branches into tubes called bronchi, which in turn branch to become progressively smaller tubes throughout the lungs.
Diseases that affect the airways include :
Asthma : The airways are persistently inflamed and may occasionally spasm, causing wheezing and shortness of breath. Allergies, infections, or pollution can trigger asthma’s symptoms.

Chronic obstructive pulmonary disease (COPD) : Lung conditions defined by an inability to exhale normally, which causes difficulty breathing.

Chronic bronchitis : A form of COPD characterized by a chronic productive cough.

Emphysema : Lung damage allows air to be trapped in the lungs in this form of COPD. Difficulty blowing air out is its hallmark.

Acute bronchitis : A sudden infection of the airways, usually by a virus.
Cystic fibrosis : A genetic condition causing poor clearance of mucus from the bronchi. The accumulated mucus results in repeated lung infections.

Question 4.
Describe about the Lung Diseases affecting the air sacs (Alveoli).
Answer:
The airways eventually branch into tiny tubes (bronchioles) that dead-end into clusters of air sacs called alveoli. These air sacs make up most of the lung tissue. Lung diseases affecting the alveoli include :
Pneumonia : An infection of the alveoli, usually by bacteria.
Tuberculosis: A slowly progressive pneumonia caused by the bacteria Mycobacterium tuberculosis.

Emphysema results from damage to the fragile connections between alveoli. Smoking is the usual cause. (Emphysema also limits air flow, affecting the airways as well.)

Pulmonary edema : Fluid leaks out of the small blood vessels of the lung into the air sacs and the surrounding area. One form is caused by heart failure and back pressure in the lungs’ blood vessels ; in another form, direct injury to the lung causes the leak of fluid.

Lung cancer has many forms, and may develop in any part of the lungs. Most often this is in the main part of the lung, in or near the air sacs. The type, location, and spread of lung cancer determine the treatment options.

Acute respiratory distress syndrome (ARDS): Severe, sudden injury to the lungs caused by a serious illness. Life support with mechanical ventilation is usually needed to survive until the lungs recover.

Pneumoconiosis : A category of conditions caused by the inhalation of a substance that injures the lungs. Examples include black lung disease from inhaled coal dust and asbestosis from inhaled asbestos dust.

Question 5.
Describe about the Lung Diseases affecting the interstitium.
Answer:
The interstitium is the microscopically thin, delicate lining between the lungs’ air sacs (alveoli). Tiny blood vessels run through the interstitium and allow gas exchange between the alveoli and the blood. Various lung diseases affect the interstitium:
Interstitial lung disease (ILD) : A broad collection of lung conditions affecting the interstitium. Sarcoidosis,idiopathic pulmonary fibrosis, and autoimmune disease are among the many types of ILD.
Pneumonias and pulmonary edemas can also affect the interstitium.

Question 6.
Describe about the Lung Diseases affecting blood vessels.
Answer:
The right side of the heart receives low-oxygen blood from the veins. It pumps blood into the lungs through the pulmonary arteries. These blood vessels can suffer from disease, as well.

Pulmonary Embolism (PE) : A blood clot (usually in a deep leg vein,deep vein thrombosis) breaks off, travels to the heart, and is pumped into the lungs. The clot lodges in a pulmonary artery, often causing shortness of breath and low blood oxygen levels.

Pulmonary hypertension : Various conditions can lead to high blood pressure in the pulmonary arteries. This can cause shortness of breath and chest pain. When no cause is identified, the condition is called idiopathic pulmonary arterial hypertension.

Question 7.
Describe about the Lung Diseases affecting the pleura.
Answer:
The pleura is a thin lining that surrounds the lung and lines the inside of the chest wall. A tiny layer of fluid allows the pleura on the lung’s surface to slide along the chest wall with each breath. Lung diseases of the pleura include :
Pleural effusion : Fluid collects in the normally tiny pleura space between the lung and the chest wall. Pneumonia or heart failure is usually responsible. If large, pleural effusions can impair breathing, and should be drained.
Pneumothorax : Air may enter the space between the chest wall and the lung, collapsing the lung. To remove the air, a tube is typically inserted through the chest wall.
Mesothelioma : A rare form of cancer that forms on the pleura. Mesothelioma tends to emerge several decades after asbestos exposure.

Question 8.
Describe about the Lung Diseases affecting the chest wall.
Answer:
The chest wall also plays an important role in breathing. Muscles connect the ribs to each other, helping the chest to expand. The diaphragm descends with each breath in, also causing chest expansion.
Obesity hypoventilation syndrome : Extra weight on the chest and abdomen makes it difficult for the chest to expand. Serious breathing problems can result.
Neuromuscular disorders : Poor function in the nerves controlling the respiratory muscles causes difficulty of breathing. Amyotrophic lateral sclerosis and myasthenia gravis are examples of neuromuscular lung disease.

Multiple Choice Questions : 1 Mark

Question 1.
Who among the following are resource creating factors as well as resources themselves?
(a) Animals
(b) Plants
(c) Human beings
(d) Nature
Answer:
(c) Human beings

Question 2
In which of the following instances does a natural event like a flood or Tsunami become a “disaster”?
(a) Only when they affect a crowded village or town
(b) When the natural events are of great intensity
(c) When they happen in the environment
(d) When they affect large uninhabited areas
Answer:
(a) Only when they affect a crowded village or town

Question 3.
The numbers, distribution, growth and characteristics of which of the following provide the basic background for understanding and appreciating all aspects of the environment?
(a) Natural resource
(b) Population
(c) Flora
(d) Fauna
Answer:
(b) Population

Question 4.
Why is it important to know how many people are there in a country, where do they live, how and why their numbers are increasing and what are their characteristics?
(a) Population is the pivotal element in social studies
(b) To exploit the natural resources of the country
(c) Human beings are producers and consumers of resources
(d) None of these
Answer:
(c) Human beings are producers and consumers of resources

Question 5.
From which of the following do we get information regarding the population of our country?
(a) Text books
(b) Survey of India
(c) Census
(d) Geological Survey of India
Answer:
(c) Census

Question 6.
Which of the following is a major concern of study about the population of a country?
(a) Population size and distribution
(b) Population growth and processes of population change
(c) Characteristics or qualities of the population
(d) All of these
Answer:
(d) All of these

Question 7.
The average number of persons per unit area, such as a square kilometre, is termed as which of the following?
(a) Population distribution
(b) Population density
(c) Absolute population
(d) Population growth
Answer:
(b) Population density

Question 8.
Which of the following reasons is responsible for uneven population distribution in India?
(a) Variations in topography or relief in different parts of India
(b) Variations in climate and rainfall distribution
(c) Variations in the rate of industrialisation and urbanisation
(d) All of the above
Answer:
(d) All of the above

Question 9.
When did the National Population Policy come into effect?
(a) 2001
(b) 1947
(c) 1952
(d) 2000
Answer:
(d) 2000

Question 10.
The unfavourable alteration of environment due to human activities is termed as
(a) ecological disturbance
(b) catastrophe
(c) ecological degradation
(d) pollution
Answer:
(d) pollution

Question 11.
Which of the following is the best indicator of SO₂ pollution
(a) bryophyte
(b) pteridophyte
(c) lichen
(d) algae
Answer:
(c) lichen

Question 12.
Heavy dust can cause
(a) leaf blights
(b) opening of stomata
(c) closure of stomata
(d) browning of leaves
Answer:
(c) closure of stomata

Question 13.
Which of the following is the major cause of pollution
(a) Plants
(b) man
(c) fungi
(d) hydrocarbon gases
Answer:
(d) hydrocarbon gases

Question 14.
Minamata disease was caused by pollution of water by
(a) mercury
(b) lead
(c) tin
(d) methyl isocyanate
Answer:
(a) mercury

Question 15.
BOD stands for
(a) biotic oxidation demand
(b) biological oxidation demand
(c) biological oxygen demand
(d) biochemical oxygen demand
Answer:
(c) biological oxygen demand

Question 16.
A river with high BOD value is
(a) highly polluted
(b) highly clean
(a) highly productive
(d) none of these
Answer:
(a) highly polluted

Question 17.
5 June is observed as
(a) world forest day
(b) world environment day
(a) world wildlife day
(d) world population day
Answer:
(b) world environment day

Question 18.
Cement factory labourers are prone to
(a) leukemia
(b) bone marrow disease
(c) asbestosis
(d) cytosilicosis
Answer:
(d) cytosilicosis

Question 19.
Noise is measured using sound meter and the unit is
(a)) hertz
(b) decibel
(c) joule
(d) sound
Answer:
(b) decibel

Very Short Answer Type Questions : 1 Mark

Question 1.
What is overpopulation?
Answer:
For a period of time, excess population in an area.

Question 2.
Which gas mostly causes global warming?
Answer:
CO₂

Question 3.
Which situation causes scarcity of food?
Answer:
Overpopulation.

Question 4.
Mention two situation due to over population.
Answer:
Deforestation, shrinkage of Agricultural land.

Question 5.
Mention two diseases of water borne.
Answer:
Hepatitis, Typhoid.

Question 6.
Name two diseases of food borne,
Answer:
Cholera, Aspergilosis.

Question 7.
Mention two ariborne diseases.
Answer:
Influenza, Pneumonia.

Question 8.
What is the cause of minamata disease?
Answer:
Due to excess amount of mercury.

Question 9.
Name two lung diseases.
Answer:
Asthma, Bronchitis.

Question 10.
Name the agent causing cancer.
Answer:
Carcenogen.

Question 11.
Name two causative agents for lung cancer.
Answer:
Pesticides, Food adulteration, smoke from industry.

Question 12.
Name two agents for Asthma.
Answer:
Pollens, dust, fungus.

Question 13.
Name the disease due to lead pollution.
Answer:
Dislexia.

Question 14.
Name the causative agent of Aspergilosis.
Answer:
Fungus.

Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 5B Environmental Pollution offer valuable context and analysis.

WBBSE Class 10 Life Science Chapter 5B Question Answer – Environmental Pollution

Short Answer Type Questions : 2 Marks

Question 1.
Why does the concentration of harmful substances increase significantly in certain location?
Answer:
Atmospheric diffusion of air is minimum at elevation of 3000 metres above earth’s surface. Many pollutants do not rise above 600 metre. Mixing and dilution of pollutants are often hampered by natural and artificial barriers. Therefore, concentration of harmful substances often becomes high in certain locations.

Question 2.
What is Acid rain?
Answer:
Oxidation of sulphur in the fossil fuels mainly produces sulphur dioxide and sulphur trioxide, which are harmful. These gases react with water to form sulphuric or sulphurous acids. The acids, when precipitated as rain or snow, create acid rain or acid precipitation.

Question 3.
How has the average temperature of the earth remained constant?
Answer:
The average temperature of the earth has remained fairly constant because there is a balance between the amount of energy received and that reflected from the earth back into space.

Question 4.
Why does the concentration of pollutants become high in certain location?
Answer:
Increase in the concentration of pollutants takes place because mixing a dilution of pollutants is hampered by artificial barriers, i.e. diffusion of pollutants above 300 metres above earth’s surface is minimal. Many pollutants do not rise above 600 metres.

Question 5.
What are particulate pollutants?
Answer:
Pollutants in the form of solid or liquid particles are known as particulate pollutants.

Question 6.
Name the major pollutants emitted by motile commercial source.
Answer:
The major pollutants emitted by motile commercial sources are carbon monoxide (77.2%), nitrogen oxides (7.7%), hydrocarbons (13.7%) and a small fraction of lead products.

Question 7.
What is the effect of sulphur dioxide on human?
Answer:
Sulphur dioxide is highly soluble in water. It enters soft tissues and causes dryness of the mouth, scratchy throat and irritation of the eyes.

Question 8.
Name the respiratory problems caused by polluted air?
Answer:

1. Bronchitis
2. Emphysema
3. Lung cancer, especially in children.

Question 9.
Name two ways by which air pollutian is controlled at the source.
Answer:
(i) By separating the pollutants from the harmless gases, and (ii) By converting the pollutants into innocuous products.

Question 10.
What is BOD?
Answer:
Biochemical Oxygen Demand (BOD) is the amount of oxygen taken up by micro-organisms in the water.
BOD is measured by keeping a sample of water containing known amounts of oxygen for five days at 20° C in the dark. At the end of five days the oxygen content is measured again.
A high level of BOD indicates intense level of microbial pollution, signifying the presence of high level of organic pollutants.

Long Answer Type Questions : 5 Marks

Question 1.
What do you mean by soil pollution?
Answer:
Soil pollution :

• Soil pollution, also called land pollution is addition or removal of nutrients which reduces the productivity of soil.
• The substances which are responsible for the reduction of soil productivity are called as soil pollutants.
• Soil pollutants alter the basic composition of the soil that may kill important soil organisms.
• There are two types of soil pollution-positive and negative soil pollution.
• When there is addition of undesirable substance in the soil then it is called as positive pollution.
• When there is reduction of soil fertility due to loss of its top layer, it is called as negative pollution.
• Negative pollution is also sometimes called third pollution or landscape pollution in which fertile land is converted into barren areas by addition of solid wastes like leather goods, spoiled food items etc.

• Pesticides, fertilizers, chemicals and radioactive wastes are the main sources of soil pollution.
• Excessive use of fertilizers causes soil deterioration through decrease of natural mircoflora. Leaching down causes pollution of underground water (third poison).
• Salts entering crop plants in excess may prove harmful.
• For example, nitrate rich leaves, fruits and water produce nitrite in alimentary canal that enters blood, combines with haemoglobin forming met-haemoglobin and reducing oxygen transport. It may prove fatal in infants.
• Soild wastes from municipalities and industries are often dumped temporarily over land. During rains heavy metals and toxic chemicals are washed down into soil and pollute the same.
• Quality of land also deteriorate due to deforestation, desertification, water logging and flooding.

Question 2.
What do you mean by pesticides?
Answer:
Pesticides include insecticides, fungicides, algicides, rodenticides and weedicides. Along with target organism they harm nontarget organism as well. This destroys the ecosystem of the soil.
Pesticides are of following types :

• Organochlorines/Chlorinated Hydrocarbons : DDT, BHC, aldrin, dieldrin and endrin. They are persistent and show biomagnification and thus prove harmful to higher trophic level organisms.
• Organo-pesticides : Degradable but toxic to workers, e.g. malathion, parathion, carbamates.
• Inorganic pesticides : They contain arsenic and sulphur and are persistent. Hence their use is highly restricted.
• Weedicides : They are persistent and harmful.

Question 3.
What do you mean by solid wastes?
Answer:
Solid wastes :
Solid wastes are discarded or left over solid materials. The terms rubbish and trash are often used interchangeably for solid waste materials. The various sources of solid wastes are municipal wastes, industrial wastes, mining wastes, hazardous wastes, defunct ships and electronic wastes.

Municipal wastes are solid wastes from homes, shops, offices, schools, street and road sweepings which are collected and disposed off by municipalities. The major components are waste paper, textiles, leather, metals, glass, plastic and polythene, food wastes etc.

Industrial wastes include scrap, effluents, sludge and flyash. Flyash is fall out from industrial emissions especially thermal plants which is often mixed with smoke. It consists of oxides of silica, aluminium and iron alongwith small quantities of heavy metals.

Mining wastes include mine dust, rock tailings, slack and slag. Toxic metals and chemicals present in the mining wastes destroy vegetation and produce many deformities in animals and human beings.

Opencast mining is a process where the surface of the earth is dug open to bring out the underground mineral deposits completely devastating the topsoil and contaminates the area with toxic metals and chemicals.

Hazardous solid wastes are generated by industries producing pesticides, rubber, dyes, chemicals, paper and metals. They are not only highly toxic to humans and other organisms but are also corrosive and highly inflammable.

Hospital wastes are full of hazardous materials like infected organic wastes, pathogens, pathogen carriers, harmful chemicals, needles, syringes, vials etc. along with some disinfectants.

Electronic wastes are irreparable computers, mobiles and other electronic goods often called e-wastes. Electronic wastes are generally sent to developing countries like India, China and Pakistan for extraction of metals through recycling.

Question 4.
Write the control of soil pollution and solid wastes.
Answer:
Control of soil pollution :

• Soil pollution can be checked by improving the disposal wastes, appropriate use of chemical fertilizers and use of biological pest.control.
• The most important measure to check land degradation is restoration of forest, crop rotation, improved drainage etc.

Control of solid wastes :

It involves collection and categorisation of wastes, transport to disposal site and disposal of waste. Disposal of waste consists of recovery and recycling, source reduction, burning and dumping.
The articles which can be recovered and recycled are tins, cans and other metal wastes, glass, plastic, polyethylene, rags, paper and cardboard.
Metal waste can be melted and purified. Broken glass is used similarly to form new glass.
Waste polyethylene is melted and recast to form new polyethylene.
In source reduction garbage and other organic wastes are taken out of urban areas and used for formation of compost, biogas and manure.
On small scale vermiculture is practised to form manure and compost.
All types of organic wastes of a town are used to prepare a manure called compost. In composting the sludge obtained after primary treatment of sewage alongwith other wastes are allowed to decompose in an open space. In 4 6 months compost is ready for use as a manure.
Cowdung and other organic wastes of farm houses can now be profitably placed in gobar gas plants which not only enrich manure but also provide gas for domestic use.
Burning is combustion of solid waste containing organic compounds in open places. It, however, produces offensive odours and air pollutants. Better methods are incineration and pyrolysis.
Incineration : It is controlled aerobic combustion of wastes inside chambers at temperature of 900-1300° C.
Pyrolysis : It is combustion inside chambers in the absence of oxygen at a temperature of 1650° C. It does not yield pollutant.
Dumping is piling of waste on selected low lying land. It is of two types, open and sanitary.
In open dumping (open landfill), waste is accumulated on uncovered low lying area and it is periodically burnt or compressed at intervals to reduce its bulk.
In sanitary dumping (sanitary landfill), the waste is pulverised, compacted or covered over by a layer of earth.

Question 5.
What do you mean by noise pollution with their sources, effect and control measures?
Answer:
Noise Pollution :
Unpleasent loud sound is called as noise (also called slow killer) and disturbing level of noise is known as noise pollution.
Annoying noise from industries, transport vehicles, agricultural machines, defence equipments, domestic gadgets, music systems, public address systems and demonstrations are various causes of noise pollution.
Noise pollution is measured in decibels.
Generally sound above 80 dB is termed as noise.
A sound more than 115 dB is harmful to the ears.
Moderate conversation has a noise value of 60 dB; scooter, buses, trucks etc. create noise of about 90 dB; jets of about 150 dB and rockets of 180 dB.
A decibel value above tolerable limit of noise is about 140 dB.
Sources of noise pollution

Main sources of noise pollution are:
Various industries such as textile mills, printing presses, engineering establishments.
Agricultural machines like tractors, harvesters, tubewells etc.
Defence equipment such as tanks, artillery, rocket launching, shooting practices, explosions.
Entertaining equipment like radios, record players, television sets.
Domestic gadgets such as desert coolers, air conditioners, vacuum cleaners, exhaust fans, mixers, pressure cooker.
Public address systems like loud speakers.
Transport vehicles like scooters, motor-cycles, ear, buses, trucks, trains, jet planes.
Dynamite blasting.
Crackers used at occasions like marriages and festivals.
Bull dozing, stone crushing, construction work etc.
Effects of noise pollution
Auditory effects
Auditory fatigue appears in the 90 dB region and greatest at 4000 Hz. It may be associated with side effects such as whistling and buzzing in the ears.
Deafness or hearing loss is the most serious pathological effect.
Further, it has been found that prolonged noise at 95 dB will produce deafness, nervous tension and rise in blood pressure.
A regular exposure to sound of 80 dB reduces hearing by 15 dB in 10 years.
Noise becomes uncomfortable above 100 dB.
Non-auditory effects
Noise interferes with speech communication. In everyday life the frequencies causing most disturbance to speech communication lie in the 300-500 Hz range. Such frequencies are commonly present in noise produced by road and air traffic.

The first effect of noise pollution is anxiety and stress reactions. Annoyance is primarily a psychological response. Neurotic people are more sensitive to noise than balanced people.

Work men exposed to higher intensities of noise in occupational capacities, were often irritated, short tempered and impatient and more likely to resort to agitation and disrupt production.
A number of temporary physiological changes occur in the human body as a direct result of noise exposure. These are a rise in blood pressure, a rise in intracranial pressure, .an increase in heartrate and breathing and an increase in sweating.
Efficiency to work decreases by noise pollution. Noise stimulates the secretion of adrenaline which increases irritability, nervousness, neuromuscular tension and feeling of fatigue, so decreasing the working efficiency.
Noise causes vasoconstriction which decreases the blood flow.
Control of noise pollution
For controlling the noise pollution, several methods have been suggested.
In metropolitan areas green belt vegetation and open space in general may have a great value in noise control as in air purification.
Green muffler scheme involves the growing green plants along roadsides to reduce noise pollution.
The enclosure of machinery with sound absorbing materials is an example of the industrial noise reduction pattern already practised by industries in advanced countries. Protection to workers can be provided through wearing devices such as a ear-plugs.
Specific legislation and regulations should be proposed for designing and operation of machines, vibrations control, sound-proof cabins and sound-absorbing materials.

Question 6.
What do you mean by ozone layer depletion and its effects?
Answer:
Ozone layer depletion
Stratosphere have a thick layer of ozone called ozonosphere which protects life on earth from harmful effects of UV radiations. Thickness of ozone is measured in Dobson unit.
Ozone in the Earth’s atmosphere is generally created by ultraviolet light striking oxygen molecules, which consist of two oxygen atoms (O₂), creating two single oxygen atoms, known as atomic oxygen. The atomic oxygen then combines with a molecule of O₂ to create ozone, O₃.
In stratosphere ozone is formed and photodissociated. It dissipates the energy of UV radiations.

Ozone absorbs most of the ultraviolet radiation, so it shields earth against biologically harmful solar radiations.
Ozone depletion refers to the phenomenon of reduction in the amount of ozone in the stratosphere. The depletion of O₃ layer by human activities may have serious implications and this has become a subject of much concern over the last few years.
Depletion in the concentration of ozone over a restricted area as over Antarctica is called ozone hole. An ozone hole was discovered over Antarctica by Farman et al, 1985 who also coined the term.
Spring time depletion of ozone is due to action of sunlight over pollutants which release chemicals (e.g., chlorine) that destroy ozone.

Thinning of ozone shield will increase the amount of UV-B radiation reaching the earth which will result in 2,50,000 more persons catching skin cancer and 5,00,000 more persons becoming blind.
Ozone depleting substances (ODS) are substances which react with ozone present in the stratosphere and destroy the same.
The ozone layer is destroyed by aerosols. Aerosols are certain chemicals released into the air with force in the form of mist or vapour.
Major aerosol pollutant present in jet plane emissions is fluorocarbon.
Besides chloroflourocarbons or CFCs (CCl₂ F₂\right. and CCl₃ F; used as coolants in air conditioners and refrigerators, cleaning solvents, aerosol propellants and foam insulation), nitrogen oxides (coming from fertilisers) and hydrocarbons are also responsible for O₃ depletion.

CFC produces active chlorine in the presence of UV radiation. These destroy ozone, converting it into oxygen. The reactions were discovered by Molina and Rowland (1974, Noble Prize, 1995 along with Crutzen). Chlorine action over ozone is chainamictics.

Effects of ozone depletion
Ultraviolet radiations are of three types UV-C (100 280 nm), UV-B (280 320 nm) and UV-A (320-390 nm).
The intermediate or UV-B are harmful as well as cayable of deeg genetration.
Thinning of ozone layer increases the amount of UV-B radiations reaching the earth.
Researches show that surface UV-B radiation inhibits photosynthesis in Antarctic phytoplanktons. This, in turn, can affect the whole food chain of organisms that depend on phytoplankton. Elevated levels of UV-B radiation affect photosynthesis, as well as damage nucleic acid in living organisms.

The various other important effects of ozone depletion are :
Cornea absorbs UV-B radiations and becomes inflamed. The disorder is called “snow blindness” cataract. It leads to diminishing of eye sight, photoburning and later permanent damage to cornea that results in actual cataract.
UV-B radiations damage skin cells, cause ageing of skin and skin cancer.
Damage of nucleic acids will increase resulting in higher number of mutatinosa.
UV radiations inhibit photosynthesis by affecting photosynthetic machinery.
Decreased photosynthetic activity will increase CO₂ concentration of the atmosphere resulting in global warming.
Both marine and terrestrial food chains will be disturbed.

Question 7.
What do you mean by greenhouse effect? Write its effect.
Answer:
Greenhouse effect :
The atmospheric greenhouse gases forms a blanket like covering around the earth. It controls the escape of heat from the earth’s surface to outer space and keeps it warm and hostile. This phenomenon is known as greenhouse effect.
It is actually a warming effect found in greenhouse by allowing solar radiations to pass in but preventing long wave heat radiations to pass out due to glass panels, water vapours and carbon dioxide. Because of it greenhouses are used for growing tropical plants in temperate areas.
The capacity of atmosphere to keep the Earth warm depends on the amount of greenhouse gases the gases which are transparent to solar radiation but retain and partially reflect back long wave heat radiations.
Greenhouse gases radiate a part of this solar energy back to the earth. The phenomenon is called greenhouse flux. Because of greenhouse flux, the mean annual temperature of earth is 15° C.
Recently the concentration of greenhouse gases has started rising resulting in enhanced greenhouse effect that is resulting in increasing the mean global temperature. It is called global warming.
The various greenhouse gases are CO₂ (warming effect 60% ), CH₄ (effect 20%), chlorofluorocarbons or CFCs (14%) and nitrous oxide (N₂ O 6%). Others of minor significance are water vapour and ozone.

Effects of green house gases
CO₂ fertilization : Increase in CO₂ concentration increases the rate of photosynthesis especially in C₃ plants. Amount of stomatal conductance will decrease resulting in lower rate of transpiration. There will be greater root growth, more mycorrhizal development and increase in N₂ fixation in root nodules. So that plants will grow more successfully in regions of water scarcity and nutrient poor soils. However, these beneficial effect will be nullified by negative effects of global warming.
Global warming : It is believed that increase in concentration of greenhouse gases has resulted in rise of atmospheric temperature. Rise in temperature will be slight in tropics, moderate in middle latitudes and maximum in polar regions (World Climate Programme, WCP, 1988).

Global warming has many fold effects as :
Effect on weather and climate: There is increase in average temperature by 1.4-5.8° centigrade by the year 2100 . Warming of atmosphere increases its moisture containing capacity. All these are responsible for change in precipitation pattern. This climatic change is harmful for human health.

Sea level change : The global warming is responsible for increase in sea level and melting of-glaciers and Greenland ice sheets.
Effects on range of species distribution : Due to increase in global warming, many species are expected to shift poleward or towards high elevation in mountain regions.

Food production : Increase in temperature causes extensive growth of weeds which ultimately decrease crop production.
Some strategies should be followed to deal with global warming:
Vegetation cover should be increased for photosynthetic utilization of carbon dioxide.
Chlorofluorocarbon should be replaced with some other substitute having little effect on global warming.
Reducing the use of nitrogen fertilizers to reduce nitrous oxide emission.
Minimizing the use of fossil fuel to reduce the greenhouse gas emission.

Question 8.
What do you mean by air pollution?
Answer:
Air Pollution

1. Oxides of Carbon : Carbon monoxide, Carbon dioxide
2. Oxides of Nitrogen : Nitrogen oxide and Nitrogen dioxide
3. Oxides of Sulphur : Sulphur dioxide and Sulphur trioxide.
4. Photochemical oxidants : Ozone, PAN (Peroxyacyl nitrate) aldehydes and other organic compounds produced by photochemical reactions between primary pollutants.
5. Hydrocarbons : Products of incomplete combustion of automobile fuel.
6. Particulate Matter : Fine solid and liquid particles, like flyash and soot from burning of coal; dust particles from industries.
7. Chemical released in vapour form as fluorocarbons, chloro-fluoromethanes.

Sources :

1. Effect-on plants : Like Chlorosis, necrosis, bleaching, premature fall of leaves, reducing photosynthetic capacity etc. leading to the damage of the crops.
2. Effects on animals and man : Like dryness of skin, congestion of respiratory tract, reduction in oxygen transport, damage to nervous system; chromosomal aberrations and cancer.
3. Climatic changes: Like Green House effect leading to global warming. Depletion of ozone layer and consequent increase in ultraviolet radiations which can cause mutations and cancer.
4. Aesthetic loss: Like spoiling the beauty of nature.

Effects :

1. Stationery combustion sources
2. Mobile combustion sources
3. Industrial processes and
4. Other sources

Question 9.
What are the sources and effects of Water Pollution?
Answer:

Sources :

1. Community waste water : as discharges from homes and commercial and industrial establishments connected to municipal sewage system.
2. Industrial waste : as chemical wastes which are discharged into rivers or streams.
3. Agricultural sources: addition of fertilisers to crops results in water pollution in water-bodies.
4. Marine pollution : navigational discharges of oil grease and petroleum products, detergents, sewage and garbage including radioactive wastes.

Effects :
The main effects of water pollution are:

1. Compounds of mercury, arsenic and lead are poisonous and they may affect the waste treatment plant.
2. Organic sulphur compounds interfere with nitrification.
3. Inorganic nitrates and phosphates stimulate excessive plant growth in lakes and reservoirs.
4. The organochlorines from pesticides are highly persistent and pass through food chains. They mainly accumulate in the nervous tissue and affect the nervous system.
5. The broad spectrum pesticides used currently cause mass destruction of aquatic life through their accidental release or excessive use.
6. Due to the presence of very fine suspended matter, water becomes unclear, unfit for drinking and industrial use.
7. Presence of free chlorine, phenol, hydrogen, ammonia, algae and microorganisms make it bad in taste and odour, and cause infection too.
8. Formation of foam due to presence of soaps, detergents and alkalies.

Question 10.
What are the effects of radioactive pollution?
Answer:
Effects of radioactive pollution
The effect of radioactive pollutants depends on :
Strength of radiations
Rate of diffusion and deposition of the pollutants
The length of time for which the tissue is exposed to radiation
Half-life of pollutants. Environmental factors (wind, temperature, rainfall) also influence their effects.
Radioactive pollution affects all the organisms including humans. It causes cancer, mutations and even death in humans and animals.
On the basis of their action on cells, radiations are divided into two categories non-ionising radiations and ionising radiations.
Non ionising radiation refers to any type of electromagnetic radiation, that does not carry enough energy per quantum to ionize atoms or molecules.
Near ultra-violet, visible light, infrared, microwave, radio waves are all examples of non-ionising radiations.
Ionising radiation consists of electromagnetic waves that are energetic enough to detach electrons from atoms or molecules ionising them.
Ionising radiations include ultra-violet rays. X-rays, cosmic rays and atomic radiations which damage the living cells by ionisation (shifting the electrons from one to other bio-molecule). Ultra-violet rays (100-300 nm) are known to cause sunburn, snow blindness, inactivation of organic bio-molecules, formation of thymine-dimer in DNA and skin cancer.
Strontium-90 behaves like calcium in biogeochemical cycling of materials in ecosystem. It accumulates in the bones to cause bone cancer and tissue degeneration in a number of organs.
Iodine-131 damages WBCs, bone marrow, spleen, lymph nodes, skin cancer, sterility and defective eye sight.
Radioactive iodine may also cause cancer of thyroid glands.
Cesium-137 brings about nervous, muscular and genetic changes.
Uranium causes skin cancers and tumors in the miners.
Actively growing and dividing cells like those of stratum germinativum, intestinal lining, bone marrow; gonads and embryo (with all cells rapidly growing and dividing) are more susceptible to ionising radiations.
A foetus in the womb may be killed by radiation which has little effect on the mother. Cancer cells are destroyed by radiation as they are of actively growing type. It has been reported that the pine seedlings are destroyed by radiations whereas the trees flourish.
Less active and non-dividing cells like osteocytes of bones, muscles fibres and neurons are not easily damaged by radiation.

Multiple Choice Questions : 1 Mark

Question 1.
Pollution is an undesirable change in physical, chemical and biological properties of
(a) Air
(b) Soil
(c) Water
(d) All of these
Answer:
(d) All of these

Question 2.
An indicator of air pollution is
(a) Lichens
(b) Mosses
(c) Ferns
(d) Pines
Answer:
(a) Lichens

Question 3.
Which of the following is the chief source of air pollution?
(a) Automobiles
(b) Burning coal
(c) Industries
(d) All of these
Answer:
(d) All of these

Question 4.
Carbon dioxide, nitrates and phosphates are
(a) Producers
(b) Decomposers
(c) Biotic substances
(d) Abiotic substances
Answer:
(c) Biotic substances

Question 5.
The hazardous metal pollutant from automobiles which hampers haemoglobin formation is
(a) NO₂
(b) SO₂
(c) Lead
(d) Mercury
Answer:
(c) Lead

Question 6.
Which of the following is an important atmospheric pollutant?
(a) Carbon monoxide
(b) Carbon dioxide
(c) Sulphur dioxide
(d) Hydrocarbon
Answer:
(a) Carbon monoxide

Question 7.
Which of the following is the least harmful pollutant?
(a) CO
(b) SO₂
(c) NO₂
(d) CO₂
Answer:
(d) CO₂

Question 8.
The presence of ozone (O₃) in the atmosphere of our earth
(a) Helps in checking the penetration of ultra-violet rays on the earth
(b) Is advantageous since it supplies O₂ for people travelling in jets
(c) Hinders higher rate of photosynthesis
(d) Both (b) and (c)
Answer:
(a) Helps in checking the penetration of ultra-violet rays on the earth

Question 9.
If BOD of a river is high, it means the river
(a) Is not polluted
(b) Is very polluted
(c) Does not have green plants
(d) Gets least amount of light
Answer:
(b) Is very polluted

Question 10.
The disease which is not caused by polluted water is
(a) Dysentery
(b) Jaundice
(c) Tuberculosis
(d) Typhoid
Answer:
(d) Typhoid

Question 11.
Which of the following is the index of pollution in a polluted lake?
(a) Algae
(b) Daphnia
(c) Frog
(d) Aquatic weeds
Answer:
(b) Daphnia

Question 12.
A powerful eye irritant present in smog is
(a) Nitric acid
(b) Peroxyacetyl nitrate
(c) Sulphur dioxide
(d) Ozone
Answer:
(b) Peroxyacetyl nitrate

Question 13.
The atmosphere pollutant which is not produced by the exhaust of motor vehicle in Delhi is
(a) Carbon monoxide
(b) Sulphur dioxide
(c) Flyash
(d) Hydrocarbon gases
Answer:
(c) Flyash

Question 14.
In Bombay, the major air pollutant is
(a) Carbon monoxide
(b) Hydrocarbons
(c) Algal spores
(d) All of these
Answer:
(a) Carbon monoxide

Question 15.
The most polluted city in the world is
(a) Tokyo
(b) New York
(c) Calcutta
(d) Mexico
Answer:
(d) Mexico

Question 16.
Which one is the major source of pollution in metropolitan cities?
(a) Pesticides
(b) Automobiles
(c) Industries
(d) Radioactive substances
Answer:
(c) Industries

Question 17.
The pollutant which directly affects the nervous system is
(a) DDT
(b) Aldrin
(c) Lindane
(d) Organic phosphate
Answer:
(d) Organic phosphate

Question 18.
Some effect of SO₂ and its transformation products on plants includes
(a) Plasmolysis
(b) Chlorophyll destruction
(c) Golgi body destruction
(d) All of these
Answer:
(b) Chlorophyll destruction

Question 19.
In the atmosphere, the accumulation of which gas does not lead to green house effect?
(a) N₂
(b) NO₂
(c) CO
(d) All of these
Answer:
(d) All of these

Question 20.
The environmental planning organisation is
(a) ICAR
(b) NEERI
(c) NCL
(d) NPO
Answer:
(b) NEERI

Question 21.
Contamination of radioactive materials are dangerous because it causes
(a) Biological magnification
(b) Gene mutation
(c) Photochemical smog
(d) Ozone destruction
Answer:
(b) Gene mutation

Question 22.
Which of the following is not an ionising radiation ?
(a) Alpha rays
(b) Beta rays
(c) UV rays
(d) Infrared
Answer:
(d) Infrared

Question 23.
The pollutant that is degradable but toxic to workers
(a) Melathion
(b) DDT
(c) Aldrin
(d) Lindane
Answer:
(a) Melathion

Question 24.
The Environment (Protection) Act to protect and improve the quality of environment (air, water and soil) was passed by the Government of India in the year
(a) 1971
(b) 1974
(c) 1981
(d) 1986
Answer:
(d) 1986

Question 25.
Which one of the following occurs in radioactive fallout and behaves like calcium in biogeochemical cycling of material in ecosystem?
(a) Strontium-30
(b) Cobalt-60
(c) Cesium-137
(d) None of these.
Answer:
(a) Strontium-30

Question 26.
Ozone prevents the entry of
(a) Infrared rays
(b) Visible rays
(c) UV rays
(d) X-rays
Answer:
(c) UV rays

Question 27.
Ozone layer of upper atmosphere is being destroyed by
(a) SO₂
(b) Chlorofluorocarbons (CFCs)
(c) CO₂
(d) Both (a) and (b)
Answer:
(b) Chlorofluorocarbons (CFCs)

Question 28.
Green muffler is used against which type of pollution?
(a) Air
(b) Soil
(c) Water
(d) Noise
Answer:
(d) Noise

Question 29.
Ozone hole refers to
(a) Reduction in the thickness of ozone layer in stratosphere
(b) Reduction in ozone layer in stratosphere
(c) Hole in the ozone layer
(d) Increased concentration of ozone
Answer:
(a) Reduction in the thickness of ozone layer in stratosphere

Question 30.
UV-B radiation from sun causes which of the following disorder of eyes?
(a) Cataract
(b) Glaucoma
(c) Dilation of pupil
(d) Some defect in retina
Answer:
(a) Cataract

Question 31.
Sound above is termed as noise
(a) 95 dB
(b) 80 dB
(c) 115 dB
(d) 140 dB
Answer:
(b) 80 dB

Question 32.
Flyash is a
(a) Mining waste
(b) Hospital waste
(c) Industrial waste
(d) Municipal waste
Answer:
(c) Industrial waste

Question 33.
Green house effect is warming due to
(a) Infrared rays reaching earth
(b) Moisture layer in atmosphere
(c) Increase in temperature due to increase in carbon dioxide concentration of atmosphere
(d) Ozone layer of atmosphere.
Answer:
(c) Increase in temperature due to increase in carbon dioxide concentration of atmosphere

Question 34.
ODS means
(a) Ozone developing substances
(b) Ozone depleting substances
(c) Ozone data source
(d) Office data secrecy
Answer:
(b) Ozone depleting substances

Question 35.
Montreal Protocol was signed in
(a) 1978
(b) 1987
(c) 1991
(d) 1993
Answer:
(b) 1987

Question 36.
Kyoto conference is connected with
(a) Limiting production of CO₂
(b) Developing alternatives to ODS
(c) Both (a) and (b)
(d) Reduction in use of energy
Answer:
(c) Both (a) and (b)

Question 37.
CFCs split up in stratosphere to release chlorine by the action of
(a) UV-A
(b) UV-B
(c) UV-C
(d) All of these.
Answer:
(c) UV-C

Question 38.
Thermal pollution causes
(a) Increase in metabolic activities of aquatic organisms
(b) Decreases in DO contents of water
(c) Oxygenation in water
(d) Both (a) and (b)
Answer:
(d) Both (a) and (b)

Question 39.
Greenhouse gases are
(a) Absorbers of long-wave heat radiations from earth
(b) Transparent to both solar radiations and long-wave radiations from earth
(c) Absorbers of solar radiations for warming the atmosphere of earth
(d) Transparent to emissions from earth for passage into outer space.
Answer:
(a) Absorbers of long-wave heat radiations from earth

Question 40.
Climate of the world is threatened by
(a) Increasing concentration of atmospheric oxygen
(b) Decreasing amount of atmospheric oxygen
(c) Increasing amount of atmospheric carbon dioxide
(d) Decreasing amount of atmospheric carbon dioxide.
Answer:
(c) Increasing amount of atmospheric carbon dioxide

Question 41.
The first effect of noise is
(a) Constriction of blood vessels
(b) Anxiety and stress reactions
(c) Increased heart beat
(d) Digestive spasm
Answer:
(b) Anxiety and stress reactions

Question 42.
Ban of DOT and start of Ganga action plan occurred in the year
(a) 1982 and 1985
(b) 1985 and 1986
(c) both in 1982
(d) both in 1985
Answer:
(b) 1985 and 1986

Question 43.
World environment day is
(a) 5th June
(b) 14th November
(c) 2nd October
(d) 28th February
Answer:
(a) 5th June

Question 44.
The worst environmental hazards created accidents in nuclear power plant and MIC gas tragedy respectively in
(a) Russia in 1990 and Bhopal in 1996
(b) Ukrain in 1986 and Bhopal in 1984
(c) Bhopal in 1994 and Russia in 1999
(d) Ukrain in 1988 and USA in 1984
Answer:
(b) Ukrain in 1986 and Bhopal in 1984

Question 45.
The ‘Earth Summit’ was held at
(a) Geneva
(b) New Delhi
(c) Sydney
(d) Rio-de-janeiro
Answer:
(d) Rio-de-janeiro

Fill in the blanks with suitable words

1. The agents that pollute the environment are called _______
2. ______ percent of atmospheric pollution is caused due to activities of modern man.
3. ______ pollutants may be solid or liquid particles.
4. Pollutants are evaluated on the basis of the amount and their relative _______
5. Ozone and nitrous compounds are _______ pollutants.
6. Oxidation of sulphur in the fossil fuels produces harmful gases ______ and _____
7. Particulate pollutants are produced as result of incomplete combustion of hydrocarbons and are ______
8. _______ serve as pollution indicators.
9. ________ is an agent or factor that causes cancer.
10. ________ are the chemicals that are released in the air with a force in the form
of mist or vapour.
11. The process of polluting streams, rivers and lakes by excessive addition of organic fertilizers is known as ________
12. ______ pollution is caused by the discharge of hot water from cooling towers of power plants.
13. _______ is a physical phenomena in which energy travels through the space.
14. ______ is the lung disease caused due to inhalation of gritty dust.
15. Threshold is the _______ is a physical phenomena in which energy travels through the space. is the lung disease caused due to inhalation of gritty dust. intensity at which a sound becomes perceptible.
Answer:
1. pollutants
2. 0.05
3. particulate
4. toxicity
5. secondary
6. SO₂, SO₃
7. carcinogenic
8. Lichens
9. carcinogen
10. aerosols
11. eutrophication
12. thermal
13. radiation
14. silicosis
15. lowest

State whether the following statements are True or False. If False, then write the correct statement.

Question 1.
Atmospheric pollution is caused due to addition of harmful substances from uncontrollable non-human sources.
Answer:
True.

Question 2.
Pollutants resulting from human activities are mainly discharged in remote and isolated areas.
Answer:
False. Pollutants resulting from human activities are mainly discharged in cities and industrial centres.

Question 3.
Vapours of compounds whose boiling point is below 200° C are classified as gaseous pollutants.
Answer:
True.

Question 4.
Lung diseases are more common in rural areas because of more air pollution.
Answer:
False. Lung diseases are more common in urban areas because of more air pollution.

Question 5.
Vapours of compounds whose boiling point is below 200° C are known as particulate.
Answer:
False. They are known as gaseous.

Question 6.
Products of atmospheric reactions of hydrocarbons and nitrogen oxides in the presence of sunlight are called secondary pollutants.
Answer:
True.

Question 7.
Atmospheric diffusion of air is maximum at elevations of 3000m above the earth’s surface.
Answer:
False. It is minimum at this altitude.

Question 8.
Dust and mist consist of particles smaller than one micrometre.
Answer:
False. They consist of particles larger than one micrometer.

Question 9.
Lead is poisonous because it hampers haemoglobin formation.
Answer:
True.

Question 10.
Nitrogen oxide impairs the functioning of lungs by causing accumulation of water in the air spaces.
Answer:
True.

Question 11 .
Ethylene gas bleaches and damages plant-leaves.
Answer:
False. Ethylene causes premature failing of leaves.

Question 12.
Abundant growth of lichens indicates pollution free air.
Answer:
True.

Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 5A Nitrogen Cycle offer valuable context and analysis.

WBBSE Class 10 Life Science Chapter 5A Question Answer – Nitrogen Cycle

Short Answer Type Questions : 2 Marks

Question 1.
What is the most abundant form under which nitrogen is found in nature?
Answer:
The most abundant nitrogen-containing molecule found in nature is molecular nitrogen (N₂). The air is 80% constituted of molecular nitrogen.

Question 2.
Under which form is nitrogen fixed by living beings?
Answer:
Most living beings cannot use molecular nitrogen to obtain nitrogen atoms: Producers fix nitrogen mainly from nitrate (N\(\mathbf{O}_3^{-}\)). Some plants also fix nitrogen from ammonia. Consumers and decomposers acquire nitrogen through digestion of mainly proteins and nucleic acids from the body of other living beings.

Question 3.
Why is leguminous crop rotation used in agriculture?
Answer:
Leguminous crop rotation and other types of crop rotation are used in agriculture because many bacteria important for the nitrogen cycle live in these plants. Leguminous crop rotation (or conjointly with the main crop) helps the soil to become rich in nitrates, which are then absorbed by the plants. Green manure, the covering of the soil with grass and leguminous plants, is also a way to improve the fixation of nitrogen and is an option for avoiding chemical fèrtilizers.

Question 4.
Define biological nitrogen fixation.
Answer:
The synthesis of organic nitrogenous compounds from atmospheric nitrogen by certain micro-organisms is called biological nitrogen fixation.

Question 5.
Why do plants need fixation of atmospheric nitrogen?
Answer:
Higher plants cannot directly utilize molecular nitrogen of the atmosphere. But certain micro-organisms can utilize atmospheric nitrogen. There are two types of nitrogen fixing micro-organisms: Asymbiotic and symbiotic.

Question 6.
What is the role of lichens in biological nitrogen fixation?
Answer:
Nostoc and Scytonema develop symbiotic association with fungi. This association is called lichens. The algal components fix the molecular nitrogen in the form of organic compounds.

Question 7.
What is the role of fungi in biological nitrogen fixation?
Answer:
Several species of Actinomycetes develop mycorrhizal association with the root of Casurina, Pinus and other plants. These mycorrhizae may be ectotropic and endotropic mycorrhizae. These fungi have ability to fix atmospheric nitrogen.

Question 8.
What is leghaemoglobin?
Answer:
The nodule is pink in colour. The pink colour is due to the presence of pigment leghaemoglobin. This pigment is synthesized by the host cells in response to bacterial infection. It is similar to haemoglobin of red blood cells of mammals.

Question 9.
Which intermediate compound is formed during biological nitrogen fixation?
Answer:
Diamide (NH=NH) and hydrazine (NH₂-NH₂) and NH₃-NH₃ are the intermediate compounds.

Question 10.
Define the following terms :
Answer:
Nitrogen fixation: The synthesis of organic nitrogenous compounds from atmospheric nitrogen by certain micro-organisms is called biological nitrogen fixation.
Asymbiotic organism : The free living nitrogen fixing organisms are called are asymbiotic organisms.
Leghaemoglobin : The nodule is pink in colour. The pink colour is due to the presence of pigment leghaemoglobin.

Long Answer Type Questions : 5 Marks

Question 1.
Describe nitrogen cycle briefly.
Answer:
The process by which limited amount of nitrogen is circulated and re-circulated throughout the world of living organisms is known as the nitrogen cycle. The chief reservoir of nitrogen is the atmosphere. Nitrogen makes up 78 per cent of the gases in atmosphere. Most living things cannot use atmospheric nitrogen. They cannot make amino acid and other nitrogen containing compounds from this nitrogen. They are dependent on nitrogen present in soil minerals. The shortage of nitrogen in the soil is the major limiting factor in plant growth. The living organism obtains nitrogen by two methods: Nitrogen fixation and decomposition.

(a) Nitrogen fixation : There are different methods to fix atmospheric nitrogen
i. Asymbiotic nitrogen fixation : The free living nitrogen fixing organisms are called asymbiotic organisms. There are following organisms which fix the atmospheric nitrogen: bacteria, anaerobic bacteria, blue green algae (cyanobacteria) and lichens. The example of anaerobic bacteria is Clostridium and the example of aerobic bacteria is Azotobacter. The example of blue green algae is anabaena.

ii. Symbiotic Nitrogen Fixation : It is the most important method of nitrogen fixation. These are of two types : Fungi (Actinomycetes) and Nodule forming Rhizobium species. Some fungi develop mycorrhizal association and fix atmospheric nitrogen. Similarly, some bacteria live in the nodule of the leguminous plants like bean, pea and gram. They fix atmospheric nitrogen.

iii. Nitrogen fixation by Electrification : The lightening of the thunder storm fixes the atmospheric nitrogen. Nitrogen and oxygen of the atmosphere combine with, each other during lightning. They form nitric oxide. It combines with more oxygen to form nitrogen peroxide. It is changed into nitric acid. Nitric acid reacts with alkalies of soil and form nitrates. These nitrates are used by the plants.

(b) Release of nitrogen by decomposition : Nitrogen is present in also present in dead plants and animals. Bacteria and fungi decompose these dead plants and animals and form nitrates and ammonia. These compounds are used up by plants. It has following steps:

i. Ammonification : The breakdown of nitrogenous compound like protein, amino acids into ammonia with the help of micro-organism like fungi and bacteria is called ammonification. Soil contains many organic materials in the form of complex organic compounds like protein, amino acids, nucleic acid and nucleotides. Most of the nitrogen formed in the soil by the decomposition of these organic compounds. Bacteria and fungi decompose these nitrogenous compounds into simple compounds. These microorganisms use the proteins and amino acids and release excess of ammonia (NH₃) or ammonium ions (NH\(\mathbf{O}_4^{+}\)). This process is known as ammonification.

ii. Nitrification : Several bacteria in soil oxidize ammonia or ammonium ions into nitrates. This oxidation is known as nitrification.

iii. Assimilation : The absorption and utilization of ammonia or nitrates by the plant is called assimilation. The plants can utilize ammonium directly. But most of the nitrogen moves from the soil into the roots in the form of nitrate. The nitrates are reduced back to ammonium in plant. This assimilation process requires energy. These ammonium ions finally transferred to carbon containing compounds. These compounds produce amino acids and other nitrogenous organic compounds.

(c) Loss of nitrogen : There are two sources of loss of nitrogen.
i. Leaching : Nitrates is soluble in water. So it is leached out of the soil by rain water. It is driven into the ground water streams, lakes and into the oceans. Some of it is utilized by algae. But some nitrogen is lost into the deep sediments and become part of the rock.

ii. Denitrification : The soil contains many denitrifying bacteria like pseudomonas, which break the nitrates and release the gaseous nitrogen into atmosphere. This process is known as denitrification.

Question 2.
Draw the word diagram of N₂ cycle.
Answer:

Question 3.
Distinguish the following terms :
Answer:

Multiple choice questions : 1 Mark

Question 1.
The conversion of nitrogen to ammonia or nitrogenous compounds is called as
(a) Nitrogen assimilation
(b) Nitrogen fixation
(c) Denitrification
(d) Nitrification
Answer:
(b) Nitrogen fixation

Question 2.
Plants absorbs N₂ in the form of
(a) nitrites (N\(\mathbf{O}_2^{-}\))
(b) nitrates (N\(\mathbf{O}_3^{-}\))
(c) ammonium (N\(\mathbf{H}_4^{+}\))
(d) all of these
Answer:
(d) all of these

Question 3.
Plants cannot absorb molecular N₂ in the atmosphere because
(a) N₂ has double bonds making it highly stable
(b) Abundance in the atmosphere inhibits absorption
(c) N₂ has triple bonds making it highly stable
(d) None of these
Answer:
(c) N₂ has triple bonds making it highly stable

Question 4.
Symbiotic N₂ fixing cyanobacteria are present in all except
(a) Anthoceros
(b) Azolla
(c) Cycas
(d) Gnetum
Answer:
(d) Gnetum

Question 5.
All the following are free living N₂ fixers except
(a) Rhizobium
(b) Azotobacter
(c) Rhodospirillum
(d) Clostridium
Answer:
(a) Rhizobium

Question 6.
Which of the following N₂ fixer is involved in symbiotic association with legumes forming root nodules?
(a) Rhizobium
(b) Azotobacter
(c) Rhodospirillum
(d) Clostridium
Answer:
(a) Rhizobium

Question 7.
Anabaena, a N₂-fixer is present in the root pockets of
(a) Marselia
(b) Salvinia
(c) Pistia
(d) Azolla
Answer:
(d) Azolla

Question 8.
Splitting of dinitrogen molecule into free nitrogen atom in biological N₂ fixation is carried out by
(a) hydrogenase
(b) nitrogenase
(c) dinitrogenase
(d) nitrate reductase
Answer:
(b) nitrogenase

Question 9.
The conversion of amino acids to ammonium by soil decomposers is called
(a) ammonification
(b) mineralization
(c) deamination
(d) Both a and b
Answer:
(d) Both a and b

Question 10.
Industrial fixation is accomplished by
(a) Helmonts process
(b) Haber process
(c) Friedel Crafts reaction
(d) Reimer Tiemann Reaction
Answer:
(b) Haber process

Question 11.
To fix one molecule of nitrogen
(a) 6 ATP molecules are required
(b) 12 ATP molecules are required
(c) 16 ATP molecules are required
(d) 20 ATP molecules are required
Answer:
(c) 16 ATP molecules are required

Question 12.
The root nodules of legumes contain a pink pigment which has high affinity for oxygen is
(a) nitric oxide (NO) haemoglobin
(b) leghaemoglobin
(c) haemoglobin
(d) bacterial haemoglobin
Answer:
(b) leghaemoglobin

Question 13.
Conversion of N\(\mathbf{O}_2^{-}\)to N\(\mathbf{O}_3^{-}\)is carried out by
(a) Nitrosomonas
(b) Nitrososcoccus
(c) Nitrobacter
(d) Clostridium
Answer:
(c) Nitrobacter

Question 14.
The process of conversion of soil \(\mathbf{O}_3^{-}\)to N₂ is called
(a) nitrification
(b) denitrification
(c) ammonification
(d) nitrogen fixation
Answer:
(b) denitrification

Question 15.
Leghaemoglobin creates
(a) Anaerobic condition for optimum activity of nitrogenase
(b) Aerobic condition for optimum activity of nitrogenase
(c) Required oxygen concentration for optimum activity of nitrogenase
(d) Suitable environment for nodule formation
Answer:
(a) Anaerobic condition for optimum activity of nitrogenase

Question 16.
Which of the followings is an anaerobic bacterium?
(a) Azotobacter
(b) Nitrobacter
(c) Clostridium
(d) None of these
Answer:
(c) Clostridium

Question 17.
Which of the followings is non-aerobic bacterium?
(a) Azotobacter
(b) Nitrobacter
(c) Clostridium
(d) None of these
Answer:
(a) Azotobacter

Question 18.
Which of the followings fixed nitrogen in waterlogged soil?
(a) Nostoc
(b) Nitrobacter
(c) Clostridium
(d) None of these
Answer:
(a) Nostoc

Question 19.
Which of the followings is a group of biological nitrogen fixing fungi?
(a) Nostacles
(b) Actinomycetes
(c) Casurina
(d) None of these
Answer:
(b) Actinomycetes

Question 20.
The nodule forming bacteria are:
(a) Azotobacter
(b) Nitrobacter
(c) Clostridium
(d) Rhizobium
Answer:
(c) Clostridium

Very Short Answer Type Questions : 1 Mark

Question 1.
Name the acids form through Natural process in N₂ cycle.
Answer:
Nitric acid, Nitrogen acid.

Question 2.
Name one bacterium which can fix N₂ symbiotically.
Answer:
Rhizobium bacterium.

Question 3.
Name one aerobic bacteria which can fix N₂.
Answer:
Azotobacter.

Question 4.
Name one anaerobic bacteria which can fix N₂.
Answer:
Clostridium.

Question 5.
Name one ammonifying bacterium.
Answer:
Bacillus mycoides.

Question 6.
Write two effects of N₂ cycle on human.
Answer:
(i) Nutrient cycle
(ii) Algal bloom in acquatic region.

Question 7.
_______ is the suspended liquid particle.
Answer:
Aerosol.

Fill in the blanks :

Question 8.
The free living nitrogen fixing organisms are called _ organisms.
Answer: asymbiotic

Question 9.
Several species of develop mycorrhizal association with the root of Casurina, Pinus and other plants.
Answer:
actinomycetes

Question 10.
Name the N₂ fixing organisms which have intermediate compounds
(a) NH=NH,
(b) NH₂-NH₂
Answer:
(a) asymbiotic
(b) actinomycetes.

Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 4B Survival Strategies: Adaptation offer valuable context and analysis.

WBBSE Class 10 Life Science Chapter 4B Question Answer – Survival Strategies: Adaptation

Short Answer Type Questions : 2 Marks

Question 1.
What is an adaptation?
Answer:
An adaptation is a way an animal’s body helps it survive, or live in its environment. Camels have learned to adapt (or change) so that they can survive. Animals depend on their physical features to help them obtain food, keep safe, build homes, withstand weather and attract mates. These physical features are called physical adaptations. They make it possible for the animal to live in a particular place and in a particular way. Each adaptation has been produced by evolution. This means that the adaptation have developed over many generations.

Question 2.
Write the examples of the basic adaptations that help creatures survive.
Answer:

• Shape of a bird’s beak
• The number of fingers
• Colour of the fur
• The thickness or thinness of the fur
• The shape of the nose or ears

Question 3.
What is a habitat?
Answer:
The surroundings where plants and animals live, is called their habitat. A habitat provides suitable climatic conditions like food and shelter so that plants and animals can live there.

Question 4.
Do all organisms live in same habitat?
Answer:
No, all organisms do not live in same habitat. Some may share the habitat e.g. lion and deer. For example camel can live in deserts only while frogs can survive in fresh/rain water.

Question 5.
Are all forests habitats of tigers or lions?
Answer:
No all forests are not habitats of tigers and lions. For example, tigers can live in forests, which have thick forests, water (ponds and streams) and rich supply of food (e.g. deer).

Question 6.
How is cactus adapted to survive in a desert?
Answer:
Cactus survives in deserts due to following adaptations-It has flat green stem to store water and prepare food by photosynthesis. The stem is also covered with a thick waxy layer, which helps to retain water. It’s roots that go very deep into the soil for absorbing water. Leaves are turned into spines to prevent loss of water.

Question 7.
Name two plants and two animals of mountain regions.
Answer:
Animals-yak, snow leopard, mountain goat. Plants-pines, spruce, fir, cedar.

Question 8.
Give an example of a non-living thing, which shows any two characteristics of living things.
Answer:
A bus or a car which shows movement and consume energy (petrol).

Question 9.
Which of the non-living things listed below, were once part of a living thing? Butter, leather, soil, wool, electric bulb, cooking oil, salt, apple, rubber.
Answer:
Following are the things which were once part of living beings :

• Butter : Obtained from milk from dairy animals.
• Leather : From animal skin of buffaloes, cows etc.
• Wool : From hair of sheep and goat.
• Cooking oil : seeds of plants (e.g. mustard) or by grinding whole plant (e.g. olive).
• Apple : fruit from apple tree.
• Rubber : Latex of rubber tree. Following things were never part of living beings-soil, electric bulb, salt.

Question 10.
List the common characteristics of the living things.
Answer:

1. Movement : All organisms show movement of one kind or another. Animals can move from one place to another. While plants also show movement e.g. bend towards light.
2. Respiration : All organisms breathe and respire. They intake oxygen and release carbon dioxide.
3. Feeding: They consume food to stay fit and grow.
4. Growth and Death: All living beings grow i.e. with age they become larger in size and eventually die.
5. Excretion : They remove waste material from their bodies.
6. Reproduction : Living beings bear children.
7. Stimuli or Sensitivity : All living beings react to external changes around them.

Question 11.
Give examples of animals which give birth to young ones.
Answer:
Humans, dogs, cats (mammals) give birth to young ones.

Question 12.
Give examples of terrestrial habitats.
Answer:
Deserts, forests, grasslands, coastal regions, mountain regions.

Question 13.
Give examples of aquatic habitats.
Answer:
Aquatic habitat includes rivers, ponds, lakes, ocean and swamps.

Question 14.
What is Acclimatization? How it is different from adaptation?
Answer:
The small adjustments by the body to overcome small changes in the surrounding atmosphere for a short period of time are called acclimatization. While in adaptation, it takes thousands of years for a living being to adapt to its habitat.

Question 15.
What are the two components of habitat?
Answer:
Biotic component, abiotic component.

Question 16.
Why is adaptation necessary? What does happen to those animals who do not adapt to the environment?
Answer:
Over thousands of years the abiotic factors of a region change. To survive animals and plants must adapt these changes. Those animals which cannot adapt these changes, die out, and only the adapted ones survive.

Question 17.
Do animals have the same kind of adaptations? Explain with an example.
Answer:
Animals adapt to different abiotic factors in different ways. For example, to survive in deserts, camels have long legs and padded feet. While desert animals like snakes and rats do not have long legs, but they stay in burrows deep in the sand and come out during night, when it is cooler.

Question 18.
What are the main morphological features of birds?
Answer:
Birds are animals with aerodynamic bodies covered with feathers, anterior limbs transformed into wings, pneumatic bones and horny (corneous) beaks.

Question 19.
In which habitat do birds live?
Answer:
Birds are terrestrial animals but the majority of them also explore the aerial environment by flying.

Question 20.
What adaptations for flight are present in birds?
Answer:
The features of birds that allow them to fly are-wings attached to a welldeveloped pectoral musculature, pneumatic bones, less accumulation of feces in the bowels due to the absence of the colon, the absence of a bladder (no urine storage), an aerodynamic body and lungs with specialized air sacs.

Question 21.
What are pneumatic bones?
Answer:
Birds have lightweight bones with internal spaces filled with air. These bones are called pneumatic bones. This feature reduces the density of body of the animal, facilitating flight.

Question 22.
How do camels adapt to their environment?
Answer:
Camels have many adaptations that allow them to live successfully in desert conditions. Deserts are hot and dry. Winds blow sand all around, so a camel has long eyelashes. It has nostrils that can open and close.

Question 23.
Why do camels have long eyelashes?
Answer:
The long eyelashes keep sand out of the camel’s eyes. Thick eyebrows shield the eyes from the desert sun.

Question 24.
Why does a camel have nostrils which can close?
Answer:
A camels nostrils can close so it doesn’t get sand up its nose.

Question 25.
What is swim bladder?
Answer:
The swim bladder, gas bladder, fish maw or air bladder is an internal gasfilled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming. The swim bladder is also of use as a stabilizing agent because in the upright position the centre of mass is below the centre of volume due to the dorsal position of the swim bladder. Another function of the swim bladder is the use as a resonating chamber to produce or receive sound.

Question 26.
What is Waggle dance?
Answer:
Waggle dance is a term used in beekeeping and ethology for a particular figure-eight dance of the honey bee. By performing this dance, successful foragers can share with other members of the colony, information about the direction and distance to patches of flowers yielding nectar and pollen to water sources or to new nest-site locations. A waggle dance with a very short waggle run used to be characterized as a distinct (round) recruitment dance.

Long Answer Type Questions : 5 Marks

Question 1.
Write the adaptive features of cactus plant.
Answer:
With desert conditions, conservation of water is extremely important to survive. Rainfall averages less than 10 inches per year. Consequently, plants have evolved ways to conserve or store water.
Among these adaptations are :

• Water storage tissues in stems or leaves.
• Leaves absent, reduced in size or short lived only when there is rain.
• Deep root systems to reach water or very wide root systems that efficiently capture water after a rainfall.
• Plants may produce a heavy thick cuticle of wax on leaves and stems to reduce water loss.
• Anatomically those plants that retain their leaves may show anatomical changes such as, reduced number of stomatas, sunken stomatas or “hairy” stomatas (protective trichomes that reduce water evaporation).
• Leaves may develop numerous trichomes (“hairs”) that shade the leaf and reduce water loss.

Question 2.
What are the physiological adaptations of a Sundry plants?
Answer:
They have a tolerance for salt water. Like xerophytes, halophytes also possess

Succulent leaves and stem
Thick walled and heavily cutinized epidermis
Hairy covering and mucilage cells.

Adaptations

• The leaves are reduced to small scaly structures (Casuarinas) or spines (Opuntia)
• The leaves are shed when water is scarce
• Water storage structures develop in the leaves
• They have a thick cuticle and a multiple layered epidermis
• They have sunken stomata
• They have long roots, which go in search of water
• The stem becomes green and takes over the function of photosynthesis where the leaves are absent/reduced/shed.

Question 3.
Write the name of air sacs of birds with their role.
Answer:

Most birds have 9 air sacs :

• one interclavicular sac
• two cervical sacs
• two anterior thoracic sacs
• two posterior thoracic sacs
• two abdominal sacs

Functionally, these 9 air sacs can be divided into anterior sacs (interclavicular, cervicals, & anterior thoracics) & posterior sacs (posterior thoracics & abdominals). Air sacs have very thin walls with few blood vessels. So, they do not play a direct role in gas exchange. Rather, they act as a ‘bellows’ to ventilate the lungs. The air sacs permit a unidirectional flow of air through the lungs. Unidirectional flow means that air moving through bird lungs is largely ‘fresh’ air and has higher oxygen content. In contrast, air flow is ‘bidirectional’ in mammals, moving back and forth into and out of the lungs. As a result, air coming into a mammal’s lungs is mixed with ‘old’ air (air that has been in the lungs for a while) and this ‘mixed air’ has less oxygen. So, in bird lungs, more oxygen is available to diffuse into the blood .

Question 4.
Write the adaptive features of camel.
Answer:
i. A camel can go a week or more without water, and they can last for several months without food.
ii. They can drink up to 32 gallon (46 litre) of water at one drinking session.
iii. Camels store fat in the hump, not water. The fat can be metabolised for energy.

iv. Unlike most mammals, a healthy camel’s body temperature fluctuates (changes) throughout the day from 34°C to 41.7°C (93°F-107°F) This allows the camel to conserve water by not sweating as the environmental temperature rises.
v. Camels feet are wide so they can walk on sand more easily. Their huge feet help them to walk on sand without sinking into it.
vi. Camels have thick lips so they can eat the prickly desert plants without feeling pain.
vii. The colour of their bodies helps them to blend into their environment.
viii. Camel’s ears are covered with hair, even on the inside. The hair helps keep out sand or dust that might blow into the animal’s ears.

Question 5.
Where the swim bladder is seen? Write the structure and role of swim bladder.
Answer:
Swim bladders are only found in ray-finned fish. In the embryonic stages some species have lost the swim bladder again, mostly bottom dwellers like the weather fish. Other fishes like the Opah and the Pomfret use their pectoral fins to swim and balance the weight of the head to keep a horizontal position. The normally bottom dwelling sea robin can use their pectoral fins to produce lift while swimming. The cartilaginous fish (e,g. sharks and rays) and lobe-finned fish do not have swim bladders. They can control their depth only by swimming (using dynamic lift); others store fats or oils for the purpose.

Structure and function : The swim bladder normally consists of two gas-filled sacs located in the dorsal portion of the fish, although in a few primitive species, there is only a single sac. It has flexible walls that contract or expand according to the ambient pressure. The walls of the bladder contain very few blood vessels and are lined with guanine crystals, which make them impermeable to gases. By adjusting the gas pressure using the gas gland or oval window the fish can obtain neutral buoyancy and ascend and descend to a large range of depths. Due to the dorsal position it gives the fish lateral stability.

In physostomous swim bladders a connection is retained between the swim bladder and the gut. The pneumatic duct allowing the fish to fill up the swim bladder by “gulping” air and filling the swim bladder. Excess gas can be removed in a similar manner. In more derived varieties of fish, the physoclisti connection to the gastric duct is lost. In early life stages, fishes have to rise to the surface to fill up their swim bladders. However, in later stages the connection disappears and the gas gland has to introduce gas (usually oxygen) to the bladder to increase its volume and thus increase buoyancy.

In order to introduce gas into the bladder, the gas gland excretes lactic acid and produces carbon dioxide. The resulting acidity causes the haemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. The blood flowing back to the body first enters a rete mirabile where virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea.

The combination of gases in the bladder varies. In shallow water fish the ratios closely approximate that of the atmosphere, while deep sea fish tends to have higher percentages of oxygen.

Physoclist swim bladders have one important disadvantage-they prohibit fast rising, as the bladder would burst. Physostomes can “burp” out gas, though this complicates the process of re-submergence. In some fish, mainly fresh water species (e.g. common carp, wels catfish), the swim bladder is connected to the labyrinth of the inner ear by the Weberian apparatus, a bony structure derived from the vertebrae, which provides a precise sense of water pressure (and thus depth), and improves hearing.

Question 6.
Write about behavioural adaptation of Chimpanzee.
Answer:
Chimpanzees live in large multi-male and multi-female social groups, which are called communities. Within a community, the position of an individual and the influence the individual has on others dictates a definite social hierarchy. Chimpanzees live in a leaner hierarchy wherein more than one individual may be dominant enough to dominate other members of lower rank. Typically, a dominant male is referred to as the alpha male. The alpha male is the highest-ranking male that controls the group and maintains order during disputes. In chimpanzee society, the ‘dominant male’ sometimes is not the largest or strongest male but rather the most manipulative and political male that can influence the goings on within a group.

Chimpanzees make tools and use them to acquire foods and for social displays; they have sophisticated hunting strategies requiring cooperation, influence and rank. They are status conscious, manipulative and capable of deception. They can learn to use symbols and understand aspects of human language including some relational syntax, concepts of number and numerical sequence and they are capable of spontaneous planning for a future state or event.

Chimpanzees also engage in targeted hunting of lower-order primates, such as the red colobus and bush babies and use the meat from these kills as a “social tool” within their community.

Question 7.
Write about the language of bees and components of the dance language.
Answer:
When an experienced forager returns to the colony with a load of nectar or pollen that is sufficiently nutritious to warrant a return to the source, she performs a dance on the surface of the honeycomb to tell other foragers where the food is. The dancer “spells out” two items of information- distance and direction to the target food patch. Recruits then leave the hive to find the nectar or pollen. Distance and direction are presented in separate components of the dance.

Distance : When a food source is very close to the hive (less than 50 meters), a forager performs a round dance. She does so by running around in narrow circles, suddenly reversing direction to her original course. She may repeat the dance several times at the same location or move to another location on the comb to repeat it. After the round dance has ended, she often distributes food to the bees following her. A round dance, therefore, communicates distance (“close to the hive,” in this example), but not direction. Food sources that are at intermediate distances, between 50 and 150 meters from the hive, are described by the sickle dance. This dance is crescent-shaped and represents a transitional dance between the round dance and a waggle dance.

The waggle dance or wag-tail dance, is performed by bees foraging at food sources that are more than 150 meters from the hive. This dance, unlike the round dance, communicates both distance and direction. A bee that performs a waggle dance runs straight ahead for a short distance, returns in a semicircle to the starting point, runs again through the straight course, then makes a semicircle in the opposite direction to complete a full figure-eight circuit. While running the straightline course of the dance, the bee’s body, especially the abdomen, wags vigorously from side to side. This vibration of the body produces a tail-wagging motion. At the same time, the bee emits a buzzing . sound, produced by wing beats at a low audio frequency of 250 to 300 hertz or cycles per second. The buzzing occurs in pulse beats of about 20 milliseconds, delivered at a rate of about 30 per second.

Direction : The orientation of the dancing bee during the straight portion of her waggle dance indicates the location of the food source relative to the sun. The angle that the bee adopts, relative to vertical, represents the angle to the flowers relative to the direction of the sun outside the hive. In other words, the dancing bee transposes the solar angle into the gravitational angle. The figure gives three examples-a forager recruiting to a food source in the same direction as the sun will perform a dance with the waggle-run portion traveling directly upward on the honey comb. Conversely, if the food source is located directly away from the sun, the straight run will be performed vertically downward. If the food source is 60 degree to the left of the sun, the waggle run will be 60 degree to the left of vertical.

Because directional information is given relative to the sun’s position arid not to a compass direction, a forager’s dance for a particular resource will change during a day. This is because the sun’s position moves during the day.

Multiple Choice Questions : 1 Mark

Question 1.
Xerophytic plants are developed in
(a) Water
(b) Land
(c) Desert
(d) Ice
Answer:
(c) Desert

Question 2.
Phylloclade is
(a) Modified leaf
(b) Modified stem
(c) Root
(d) Flower
Answer:
(b) Modified stem

Question 3.
In cactus, leaves are modified into
(a) Tendril
(b) New plant
(c) Apines
(d) Stipule
Answer:
(c) Apines

Question 4.
The swim bladder is present in
(a) Chondrichthyes
(b) Rayed finned bony fish
(c) Aquatic mammals
(d) Scoliodon
Answer:
(b) Rayed finned bony fish

Question 5.
Number of air sacs in Pigeon is
(a) 8
(b) 9
(c) 10
(d) 7
Answer:
(b) 9

Question 6.
Trophic movement in breathing root is
(a) Positively phototrophic movement
(b) Negatively geotrophic movement
(c) Positively geotrophic movement
(d) Tacticative movement
Answer:
(b) Negatively geotrophic movement

Question 7.
In camel metabolic water comes from
(a) Protein
(b) Fat
(c) Carbohydrate
(d) Stored water in stomach
Answer:
(b) Fat

Question 8.
After parasitic attack, chimpanzee consumes
(a) Medicinal plant
(b) Medicines
(c) Water
(d) Protein
Answer:
(a) Medicinal plant

Question 9.
Waggling movement is seen in
(a) Chimpanzee
(b) Bees
(c) Human
(d) Cat
Answer:
(b) Bees

Question 10.
The hydrostatic organ is
(a) Air sac
(b) Swim bladder
(c) Spine
(d) Pneumatophore
Answer:
(b) Swim bladder

Very Short Answer Type Questions : 1 Mark

Question 1.
What is phylloclade?
Answer:
Modified stem.

Question 2.
In cactus, leaves are modified into which part?
Answer:
Leaves are modified into spine.

Question 3.
Name the hydrostatic organ of rohu fish.
Answer:
Swim bladder.

Question 4.
How many air sacs are present in Pigeon?
Answer:
9 air sacs.

Question 5.
Name one animal where double respiration is seen.
Answer:
Pigeon.

Question 6.
Name the soil where halophytes are developed.
Answer:
Physiologically dry soil.

Question 7.
Name pores present on the breathing root.
Answer:
Pneumatophores.

Question 8.
Name one mammal where RBC is nucleated.
Answer:
Camel.

Question 9.
In camel metabolic water is coming from
Answer:
Fat.

Question 10.
Which tool is used by chimpanzee to break nuts?
Answer:
Hammer.

Question 11.
Waggle dance by bees form which shape?
Answer:
‘8’ shape.

Question 12.
Dance is performed by which caste of bees?
Answer:
Worker.