Detailed explanations in West Bengal Board Class 8 Science Book Solutions Chapter 8 Human Food and Food Production offer valuable context and analysis.
WBBSE Class 8 Science Chapter 8 Question Answer – Human Food and Food Production
Multiple Choice Questions & Answers : (1 mark for each question)
The fowl that do not incubate eggs …………….
Fish that is imported from foreign countries …………….
ii) Grass Carp
ii) Grass Carp
The fowls that produce eggs and meat …………….
iv) Rhode Island Red
iv) Rhode Island Red
Mrigel and Common carp collect food in water from …………….
i) upper layer
ii) middle layer
iii) lower layer
iii) lower layer
According to the location of fish production fisheries are of …………….
i) two types
ii) three types
iii) four types
iv) many types
i) two types.
Example of major carp …………….
iv) silver carp
Silver Carp is …………….
i) Major Carp
ii) Minor Carp
iii) Exotic Carp
iii) Exotic Carp
A kharif crop …………….
In their head fishes contain …………….
i) pituitary gland
ii) thyroid gland
iii) postrate gland
i) pituitary gland.
a fibre crop …………….
Green tea contains …………….
i) vitamin B complex
ii) vitamin C
iii) vitamin A
iv) vitamin K
iv) vitamin K
A cereal crop is …………….
Which one is a decorative plant?
King of fruits …………….
A Rabi Crop …………….
State whether True or False : (1 mark for each question)
1. Trailer is used for removing weeds and loosening the soil.
2. Small farmers use winnowing to separate grains from the chaff.
3. The food of the domestic animal is known as fodder.
4. Fresh crop has less moisture.
5. Infestation of the microbes can occur, if freshly harvested grains are stored without drying.
6. Presently oxygen gas is continuously circulated through the granaries.
7. Maize is an important crop of the world.
8. Paddy is one of the major food crop of India.
9. Aush paddy seeds are directly sowed in the agricultural field.
10. Swarna, Masuri paddy mature within 95-115 days.
Fill in the blanks : (1 mark for each question)
1) Take branch of science in which the process of food production is discussed is ………….
2) When plants of the same kind are cultivated in a large area, the plants are collectively termed as ……….
3) The branch of agriculture in which the process of fruit and vegetable cultivation is discussed is called ………….
4) …………. and other microbes that live in the soil act as farmer’s friend.
5) ………… is used for removing weeds and loosening the soil.
6) ………… manure is produced by decomposition of dead plants and animal wastes.
7) …………. fertilisers are chemical substances.
8) The supply of necessary water to the crops in the field at definite intervals is termed as ………….
9) A big well and a wheel are used in …………. method.
10) The unnecessary plants that grow in the agricultural field are termed as ………….
11) The cultivation of …………. crop generally starts from the beginning of monsoon.
12) The cultivation …………. crops starts from the beginning of winter.
13) The …………. fly in hordes and cause severe damage to the crops like sugarcane, wheat by feeding on their leaves.
14) Fungi produce …………. disease in wheat and disease in potato.
15) Animals like rats can be controlled by…………. and ………….
16) …………. is an important job after the crop gains maturity.
17) Harvesting and threshing both can be done with the help of a machine called………….
18) The food of the domestic animals is known as ………….
19) ………….is one of the major food crop of India.
20) …………. paddy cultivation is more in West Bengal.
21) …………. is indigenous to India.
22) The original abode of tea is the basin of …………. river in South-east Asia.
23) We get…………. and …………. from honey-bee.
24) …………. honey bee collect nectar from flowers.
25) The culture of fishes arc called ………….
26) Birds which have economic importance at …………. called birds.
27) The female fish releases and the male fishes release the …………. when injected with pituitary extract.
28) Sperms and eggs unite to produce………….
29) Cotton is a…………. crop.
30) Black pepper is a ………….crop.
14) rust, blight
15) Zinc phosphide, warfarin
23) honey, wax
27) eggs, sperms
Match the column A with column B
|Column A||Column B|
|a) Tea is a||i) when organic manure is used|
|b) Hoc is used for removing weeds||ii) the roots of plants|
|c) Seed drill is a||iii) important commercially|
|d) Inorganic fertilisers are manufactured||iv) with queen honey bee|
|e) The soil becomes porous||v) and loosening the soil|
|f) Termites feed on||vi) plantation crop|
|g) High fluride content in tea leaves||vii) are reared for economic gain|
|ii) Male honeybee takes part in breeding||viii) in fertiliser factories|
|i) Minor carps are not||ix) prevents tooth decay|
|j) Birds like ducks and fowls||x) sowing tool|
a) Tea is a plantation crop.
b) Hoc is used for removing weeds and loosening the soil.
c) Seed drill is a sowing tool-.
d) Inorganic fertilisers are manufactured in fertiliser factories.
e) The soil becomes porous when organic manure is used.
f) Termites feed on the roots of plants.
g) High fluride content in tea leaves prevents tooth decay.
h) Male honeybee takes part in breeding with queen honeybee.
i) Minor carps are not important commercially.
j) Birds like ducks and fowls are reared for economic gain.
Very Short Questions & Answers : (1 mark for each question)
Write names of two fibre crops :
Cotton. Jute are two fibre crops.
Write names of two oil seeds.
Mustard. Sunflower are two oil seeds.
Write names of two spice crops.
Black pepper. Ginger are two spice crops.
What type of crops are Neem and Tulsi?
These are medicinal crops.
Give example of two tuber crops?
Potato and ginger are two tuber crops.
Name two crops from which we get sugar.
Sugarcane and Beet are two crops from which we get suger.
What type of crops are Gram, Peas and Beans?
Gram, Peas and Beans are pulses.
Give example of two Plantation crops.
Tea and Coffee are two plantation crops.
What is horticulture?
The process of fruit and vegetable cultivation is discussed in a branch Horticulture.
Write names of three vegetables.
Tomato, Cabbage, Brinjal are three vegetables.
Name two decorative plants.
Cactus, Bougainvillea are two decorative plants.
Give example of three Bower plants.
Rose, Jasmine. Marigold are three flower plants.
When cultivation of Kharif crops start?
The cultivation of Kharif crops start from the beginning of monsoon (June/July).
On which monsoon the production of Kharif crops depend?
The production of Kharif crops depend upon the South-west monsoon.
Give some examples of Kharif crops?
Some examples of Kharif crops are paddy, maize, cotton, groundnut, soyabean etc.
When cultivation of Rabi crops start?
The cultivation of Rabi crops start from the beginning of winter (October/November).
When Rabi crop is harvested?
The Rabi crop is harvested in the month of March/April.
Give some examples of Rabi crops?
Some examples of Rabi crops are wheat, barby, gram, pea, mustard etc.
What is termed as Agricultural practices?
The activities or tasks that a farmer does is termed as Agricultural practices.
What are a soil contains?
The soil contains different minerals, water, air, humus and different organisms.
What is called friend of farmers?
Earthworm is called friend of farmers.
What is ploughing?
The process of turning and loosening the soil is called ploughing.
How is Hoe used?
Hoe is used for removing weeds and loosening the soil.
What is used nowadays to plough large tracts land?
Presently the help of tractor is taken to plough large tracts of agricultural land.
What is used nowadays to plough small agricultural land?
For ploughing small agricultural land or flower garden nowadays power tiller is used.
How is seed drill used?
Seeds can be sowed at the right distances and at requisite depths with the help of seed drill.
Why the farmers dip the seeds in chemicals before sowing?
The farmers dip the seeds in chemicals before sowing as these chemical substances reduce the chances of infection of the seeds.
What are plant nutrients?
Plants require some minerals for proper growth-these are termed as plant nutrients.
How many types of manure and fertilisers are there?
They are of two types-organic manure and inorganic fertilisers.
How organic manure is produced?
Organic manure is produced by decomposition of dead plants and animal wastes.
Cultivation of which crop increases nitrogen in soil?
Cultivation of leguminous plants (pea, bean, gram, pulses) increases nitrogen in soil.
What is crop rotation?
Cultivation of other crops like leguminous plants in between the cultivation of two similar type of crops is termed as crop rotation.
Write name of some common weeds.
Some common weeds are-Parthenium, Amaranthus, Chenopodium, Grass etc.
What are two ways to control the pests?
There are two ways to control the pests → chemical and biological.
What type of chemicals are used to control rats?
Chemicals like zinc phosphide and warfarin are used to control rats.
Which chemicals control the insects?
DDT, BHC. Malathion helps in controlling the insects.
Name some natural predators of some pests.
Some types of spiders, wasps, hornets, grasshoppers and some kinds of birds are natural predators of some pests, like-moths, sapsucking insects, termites etc.
What is threshing?
Edible part of the grain crops need to be separated from the plants, this is termed as threshing.
Presently which gas is used in granaries?
Presently nitrogen gas is continuously circulated through the granaries, as a result the pests find it difficult to survive due to lack of oxygen.
Which is the major food crop of India?
Paddy is one of the major food crop of India.
What is the nutritive value of rice?
Rice contains 79 1% carbohydrate, 6% protein, 011% different elements, Vitamin B complex and some other vitamins.
What is produced from rice bran?
Oil is produced from rice bran.
What are the types of paddy based on the generic variety and method of cultivation?
These are Aush or Autumn paddy, Aman or Winter paddy and Boro or Summer paddy.
What are the types of paddy based on the production capacity?
Based on the production capacity paddy are of two types.
When Aman paddy is cultivated?
Aman paddy is cultivated during the Monsoon season.
Name some good varieties of indigenous Aman paddy.
Good varieties of indigenous Aman paddy-Bhashamanik, Jhingasal, Raghusal, Patnai- 23. Basmati etc.
When Boro is harvested?
Boro is harvested in March-April.
How much time Ratna Paddy takes to nature?
Ratna Paddy mature within 95-115 days.
How much time .lava, Jayanti Paddy takes to mature?
Jaya, Jayanti Paddy mature within 116-135 days.
Name some varieties of Nabi or Long duration variety Paddy.
Some varieties of Nabi or Long duration variety Paddy are Swarna. Masuri, Pankaj etc.
What is golden rice?
Golden rice is a special types of Paddy created by agricultural scientists to meet the demand of Vitamin A.
What is the birth place of Mango?
India is the birth place of Mango.
In which places Mango is cultivated in West Bengal?
In West Bengal Mango is cultivated mostly in Makla, Murshidabad and Nadia.
What type of soil is suitable for Mango cultivation?
Alluvial soil of river basin and fertile loamy soil is the most suitable for Mango cultivation.
What are the different ways of grafting done in Mango?
Grafting done in Mango in various way-lnarching. Veneer grafting. Chip budding. Stone grafting.
Name Some varieties of Mango.
Some varieties of Mango are Himsagar, Bombai, Langra, Golapkhas, Chausa etc.
What are the World’s largest tea producing countries?
World’s largest tea producing countries are China. India. Kenya, Srilanka and Turkey.
Name the main tea producing states of India.
The main tea producing states of India are Assam. West Bengal. Tamilnadu and Kerala.
What are the famous tea of India?
The famous tea of India is Darjeeling. Assam and Nilgiri.
How are tea plants propagated?
Tea plants are propagated both from seeds and plant parts.
How many types of commercial tea are there based on the method of manufacture?
They are of three types- Black tea. Green tea and Oolong tea.
What we get from honey bees?
We get honey and wax from honey bees.
Name the types of honey bees present in honey bee society.
They are queen honey bee, male honey bee and worker honey bee.
What is the nutritional value of honey?
honey contains lots of glucose and fructose, amino acids, other minerals (Na, K, Ca, Fe, Mg, P), vitamin A, B-complex and C.
What are the four stages of life of honey bee?
Four stages of life of honey bee are-egg, larva, pupa and adult.
What is apiculture?
Rearing of honey Bees in a scientific and artificial way is termed as apiculture.
What is apiary?
Rearing place for the honey bees, be it natural or artificial is termed as apiary.
What the culture fishes are called?
The culture fishes are called Pisciculture.
What is fertilisation.
The process of unification of eggs with the sperms is called fertilisation.
Name the ponds the spawns are reared one after another.
These ponds are termed as nursery pond, rearing pond and stocking pond.
What is composite fish culture?
Culture of three types of indigenous fishes in one single pond is termed as Composite Fish culture.
What is Composite Mixed Fish Culture or Polyculture?
Culture of three types of indigenous carps with three types of exotic carps in one single pond is termed as Composite Mixed Fish culture or Polyculture.
What is the primary food of fishes?
The primary food of fishes are phytoplanktons.
What is sewage?
Generally water of black colour mixed with waste materials from houses, municipalities and factories is termed as sewage.
What is sewage used for?
Sewage is used for fish culture in the Vheris in East Kolkata.
What is nutritional value of fish?
Fishes supply animal protein, essential amino acids, fatty acids, various minerals (eg. Ca, P, Na, K. Mg. S) and some vitamins (A, C. D and B-Comple.).
What is Broiler?
Broiler is a type of hybrid fowl bird created for only getting meat.
Short Questions & Answers : (2 marks for each question)
What arc the types of paddy, based on the time needed for maturity?
- Jaldi or Early duration varieties
- Majhari or Medium duration varieties
- Nabi or Long duration varieties.
Why are manure and fertilisers added to soil?
The plant nutrients present in the soil are depleted when the same land is used for repetative cropping. For this reason, manure and fertilisers are added to the agricultural land. This ensures that the soil gets back the lost nutrients.
What requirements are l’ulfdled by Inorganic fertilisers?
Inorganic fertilisers mainly meet the requirement of three types of elements – nitrogen (N), phosphorus (P) and potassium (K).
What harm occurs if ammonium sulphate and sodium nitrite is not used in accordance with the properties of the soil?
Ammonium sulphate [(NH4)2SO4] increases the acidity of the soil and Sodium nitrite (NaNO2) increase the alkalinity of the soil.
What is irrigation?
Maintenance of soil humidity is essential for getting a good production. For this reason, it is necessary’ to supply water to the crops in the field at definite intervals. This is termed as irrigation.
What are weedicides?
Weeds are also controlled by spraying some chemicals (2, 4-D, Dalapon. Picloram etc). These chemical substances are called weedicides.
How many plant nutrients are there? What are they?
The plant nutrients are of two types :
- Macronutrients – C, H, O, N, P, K, Mg, S
- Micronutrients – Ce, Mil, Cu, B. Mo. Zn, Cl.
What is grafting?
Grafting is a kind of propagation in plant made in the artificial way. In grafting a new plant is produced from a part of the plant.
What is fodder?
Parts of the stem that remain in the ground after the crop is harvested and the chaff are fed to the domestic animals. This food of the domsestic animals is known as fodder.
What is the nutritional value of Mango?
Mango contains protein, fat and minerals (Ca. P. Fc) etc. It also contains Vitamin A, B- Complex and C, water, fibres and phyto chemicals (Beta-Carotene).
What is hot chery?
The fertilised eggs collected by the fish farmers are reared in a pond to produce spawns. This pond is termed as the hot chery.
What is animal husbandry?
To get animal-based food products regularly and sufficient quantities, those animals need to be reared with care and along with arrange for their breeding, this is animal Husbandly’.
What are pests? Name some of them.
Rats, various insects feed on the crops or damage the crops, they are termed as pests. Some pests are-locust, termite, weevil, stem borer etc.
What is NPK?
NPK is inorganic fertiliser which has thee components-nitrogen (N), phosphorus (P) and potasium (K) mixed in differant proportions. This help in the growth of plant.
Long Questions & Answers : (3 marks for each question)
Describe the topics that arc relevant to Agriculture.
- Soil management, i.e to make soil suitable for production of crops.
- Crop production
- Horticulture, i.e cultivation of fruits, vegetables, flowers and decorative plants.
- Animal Husbandry.
List the activities that a farmer has to perform to produce crops.
- Preparation of soil of cultivable land
- Sowing of seeds
- Adding manure and fertilisers
- Protection from weeds
- Protection from pests
What is a plough?
Plough has been used in cultivation for a long time. Plough is used for ploughing the field, mixing fertilisers with the soil or removing weeds. Presently indigenous wooden ploughs are gradually being replaced by ploughs made of iron.
Briefly describe how the farmers sow seeds? also explain why?
Sometimes the farmers dip the seeds in chemicals before sowing. These chemical substances reduce the chances of infection of the seeds. Seeds of paddy and some vegetables (tomato, onion) are sowed first in seed-beds.
After the seedlings have grown a bit in the seed-bed, healthy, strong and disease-free seedlings are selected and planted in the agricultural field. Seedlings of improved quality can thus be selected. The transplanted seedlings are also able to penetrate their roots deep in the soil. As a result the production also increases.
What are the problems in using inorganic fertilisers?
- Excessive and indiscriminate use of inorganic fertilisers create problems in the functioning of soil-living beneficial bacteria. Thus, the soil fertility is reduced.
- Inorganic fertilisers sometimes change the soil chemestry. Like ammonium sulphate ((NH2SO4) increases the acidity of the soil whereas sodium nitrite (NaNO2) can increase the alkalinity of the soil.
- River or pond water near agricultural field becomes polluted by coming or contact with nitrogen or phosphorus compound present in inorganic fertilisers.
Why organic manure is better than inorganic fertilisers?
- Organic manure increases the water retention capacity of the soil.
- The soil becomes porous when organic manure used.
- Organic manure helps to increase the number of beneficial microbes present in the soil.
- Organic manure improves soil texture.
What are biofertilisers?
Sometimes various microbes are mixed with the soil to maintain the nutrients present in the soil. This is termed as biofertilizers. Biofertilisers increase the water retaining capacity of the soil. They make the soil porous and increase aeration in the soil.
Why is irrgation essential for plants?
Irrigation is essential because-
- Water is needed for the growth of plants and development of flowers fruits and seeds.
- Plants take various nutrients and fertilisers from the soil through water.
- The nutrients reach different plant organs mixed with the water.
- Water is very essential for the germination of seeds.
- Maintenance of soil humidity is essential for getting a good production.
How irrgation is done in fields?
Two methods of irrigation is done in fields-
i) Traditional methods : Human or animal labour is generally used in the traditional methods of irrigation.- Some such methods are-
- Rope-bucket-pulley-moat method,
- Swing basket method
- Chain pump method
- Dhekli method
- Persian wheel or Rabat method.
ii) Modern method : Traditional methods are cheaper, but are less effective and misuse of water happens. Misuse of water can be reduced by modern methods. Some such methods areal Sprinkler
- system: water is sprinkled on the crops like a fountain.
- Drip system: water is supplied near the foots of the plants in drop by drop manner with the help of a pipe.
What are the problem of controlling pests with chemicals like DDT, BHC etc?
- The pests can develop resistance against a specific chemical.
- The chemicals may cause water pollution by mingling with the water of rivers or lakes.
- Organisms at the end of the food chain can be harmed if these chemicals enter the food chain.
- These chemicals can harm human beings if they enter the human body through fruits and vegetables.
- The chemicals sometimes kill beneficial insects (honeybees, butterflies)
How biological control method is used to control pests?
In biological control method an organism is used in controlling the number of another organism in this method. The help of predators and parasites are taken to control the pests. Some types of spiders, wasps, hornets, grasshoppers and some kind of birds are nature predators of some pests (like moths, sap-sucking insects, termites etc) Some fungi, protozoa bacteria and viruses live as parasites inside the body of the pests and control the pest population.
Describe briefly how Inarching is done in mango.
Inarching grafting is done by joining a branch of a high quality mango tree (scion) with a seedling (stock) produced from mango seed. Generally this grafting is done in July-August (Bengali month Ashar).
- Some part is cut from both the seedling and the branch of the high quality mango tree. Then they are joined in the cut portion with a string. The seedling is watered regularly till the joining is complete,
- After the joining is complete, the lower portion of the scion below the joined part and upper portion of the seedling above the joined part is cut of in 2 or 3 phases.
- The plant produced by inarching is kept in the shades for some days. Then it is transplanted in the nursery.
Write four nutritional value of tea.
- Drinking tea stimulates the body due to the presence of caffeine
- Tea cantains Havonoids, tannis. volatile oils and vitamin B. which are good for health.
- High fluoride content in tea leaves prevents tooth decay.
- Black tea contains high amounts of vitamin B-complex and folic acid which are anti-ulcer and anti-carcinogenic in nature.
Describe the different types of work done by the different types of honeybees.
Each of the three types of honeybee has specific job-
- queen honeybee lays egg.
- Male honeybee takes part in breeding with queen honeybee,
- Worker honeybee has many jobs to do-constructing beehive, collecting pollen grains and nectar, taking care of queen and male honeybees, producing honey and wax, rearing the young ones, guarding the beehive.
How do the honeybees construct the beehive and produce honey?
Worker honeybee has a wax gland in their abdomen. They construct the beehive with the secretion of the wax gland. Numerous hexagonal chambers are present in each beehive. Worker honeybees collect necter from flowers. They store the nectar in the honey sac of their own body.
In the honeysac, saliva mixes with nectar. As a result, some changes occur in the carbohydrates present in nectar. Warker honeybee vomits this mixture in the honey chamber and fan it with their wings. As a result water is vapourised, thus producing honey.
What are carps? How many types of carps are there?
Carps are those bony fishes living in fresh water characterised by the absence of scales on triangular head, accessory respiratory organ, tooth in the jaw and the presence of swim bladder in their body. For example, Rohu, Catla, Bata etc. Carps can be divided in two types :
i) Indigenous carp →
- Major Carp
- Minor Carp.
ii) Exotic carp.
Differentiate between Major earp and Minor carp.
|Major carp||Minor carp|
|i) Big in size.
ii) Grows quickly.
Generally do not spawn in enclosed water.
iii) They are commercially important and their demand is also more. Example : Rohu, Catta
|i) Small in size.
ii) Do not grows quickly.
Generally spawn in enclosed water.
iii)They are not important commercially.
Example : Bata, Punti etc.