Class 9

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 1.3B Five Kingdoms of Life can serve as a valuable review tool before exams.

Five Kingdoms of Life Class 9 WBBSE MCQ Questions

Multiple Choice Questions & Answers

Question 1.
Nuclear membrane and nucleolus is absent in- ………………
A. Kingdom Monera
B. Kingdom Protista
C. Kingdom Plantae
D. None of these
Answer:
A. Kingdom Monera

Question 2.
Cell wall is absent in-………………
A. Kingdom Monera
B. Kingdom Animalia
C. Kingdom Plantae
D. None of these
Answer:
B. Kingdom Animalia

Question 3.
Almost all members of this kingdom are capable of synthesising their own food. This kingdom is-………………
A. Kingdom Protista
B. Kingdom Fungi
C. Kingdom Monera
D. Kingdom Plantae
Answer:
D. Kingdom Plantae

Question 4.
According to five kingdom classification, dinoflagellates belong to the kingdom-………………
A. Monera
B. Fungi
C. Protista
D. Plantae
Answer:
C. Protista

Question 5.
Cell wall is rich in chitin in the members of-………………
A. Kingdom Plantae
B. Kingdom Fungi
C. Kingdom Protista
D. Kingdom Monera
Answer:
B. Kingdom Fungi

Question 6.
Spirogyra is a filamentous-………………
A. Alga
B. Fungus
C. Plant
D. Worm
Answer:
A. Alga

Question 7.
Mucor is a-………………
A. Unicellular fungus
B. Multicellular alga
C. Multicellular fungus
D. Unicellular alga
Answer:
C. Multicellular fungus

Question 8.
Penicillium share same kingdom with-………………
A. Spirogyra
B. Bacteria
C. Mucor
D. Volvox
Answer:
C. Mucor

Question 9.
Whittaker inciuded Chlamydomonas under kingdom-………………
A. Fungi
B. Protista
C. Plantae
D. Animalia
Answer:
C. Plantae

Question 10.
Cyanobacteria can perform photosynthesis, still Whittaker placed it under kingdom-………………
A. Monera
B. Protista
C. Plantae
D. Fungi
Answer:
A. Monera

Question 11.
Members of this kingdom have their cell wall made up of polysaccharides and amino acids. This kingdom is-………………
A. Monera
B. Plantae
C. Protista
D. Fungi
Answer:
A. Monera

Question 12.
Saprophytic or parasitic mode of nutrition is seen in the members of kingdom-………………
A. Fungi
B. Protista
C. Plantae
D. Animalia
Answer:
A. Fungi

Question 13.
Multicellular heterotrophic organisms without cell wall, come under kingdom-………………
A. Protista
B. Plantae
C. Fungi
D. Animalia
Answer:
D. Animalia

Question 14.
Non-photosynthetic multicellular organisms with cell wall belong to kingdom-………………
A. Animalia
B. Plantae
C. Fungi
D. None of these
Answer:
C. Fungi

Fill in the blanks:

1. The five kingdom classification of living world was proposed by scientist ………………..
2. Unicellular eukaryotic animals are included under kingdom ………………..
3. Penicillium belongs to the kingdom …………….
4. Prokaryotic cells belong to kingdom …………….
5. Kingdom possess the highest level of biodiversity……………..
6. Euglena has been placed under kingdom ……………. according to five kingdom classification.
7. The concept of two kingdom classification was introduced in the year …………….
8. Mycoplasma is placed under the kingdom …………….
Answer:
1. Whittaker
2. Protista
3. Fungi
4. Monera
5. Animalia
6. Protista
7. 1758
8. Monera

State True or False

1. Two kingdom classification was proposed by Zimmerman. — False
2. Diatoms belong to the kingdom Protista. — True
3. The symbiotic relationship between a fungus and an alga is known as lichen. — True
4. Cyanobacteria belong to kingdom Protista. — False
5. Paramoecium belongs to the kingdom Monera. — False
6. Mycelium is seen in fungus. — True

Match the columns

Left column	Right column
1. Amoeba	A. Cyanobacteria
2. Euglena	B. Pseudopodia
3. Rhizopus	C. Mushroom
4. Nostoc	D. Flagella
	E. Mycelium

Answer:
1-8; 2-B; 3-E; 4-A

Left column	Right column
1. Sidney Fox	A. Systema Naturae
2. John Ray	B. Father of Botany
3. Carolus Linnaeus	C. Microsphere
4. Charles Darwin	D. Concept of species
	E. Natural selection

Answer:
1-C: 2-D: 3-A: 4-E

Left column	Right column
1. Paramoecium	A. Animalia
2. Penicillium	B. Protista
3. Bear	C. Monera
4. Bacteria	D. Fungi
	E. Plantae

Answer:
1-D; 2-A; 3-E; 4-B

Left column	Right column
1. Green plants	A. Decomposers
2. Fungi	B. Parasite
3. Animals	C. Scavenger
4. Mosquito	0. Autotrophs
	E. Consumers

Answer:
1-D; 2-A; 3-E; 4-B

 

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 5.1 Ecology and Ecological Organisations can serve as a valuable review tool before exams.

Ecology and Ecological Organisations Class 9 WBBSE MCQ Questions

Multiple Choice Questions :

Question 1.
Branch of science dealing with the interrelation of a species and its environment is-
(A) Autecology
(B) Synecology
(C) Community biology
(D) Population biology
Answer:
(A) Autecology

Question 2.
Synecology deals with –
(A) A single individual
(B) A population
(C) A community
(D) Different ecosystems
Answer:
(C) A community

Question 3.
At which level of ecology would you explain the event of change in body colour of an animal with the change in intensity of light?
(A) Individual level
(B) Population level
(C) Community level
(D) Ecosystem level
Answer:
(A) Individual level

Question 4.
Synthesis of chlorophyll in green plants is controlled by-
(A) Relative humidity
(B) Atmospheric pressure
(C) Temperature
(D) Light
Answer:
(D) Light

Question 5.
The similarity amongst chlorophyll production, transpiration rate and opening of stomata is that-
(A) All are involved in growth of plants
(B) All are light dependent events
(C) All increase weight of plant body
(D) All decrease weight of plant body
Answer:
(B) All are light dependent events

Question 6.
All the plants and animals together of a particular area are called-
(A) Ecotone
(B) Biome
(C) Biota
(D) Echod
Answer:
(C) Biota

Question 7.
Absorption of water by plants is related to-
(A) Water content of soil
(B) Chlorophyll concentration
(C) Plant height
(D) Starch content of cells
Answer:
(A) Water content of soil

Question 8.
Xerophytes have-
(A) Thick cuticle cover
(B) Less stomata
(C) Thick stem hair
(D) All of these
Answer:
(D) All of these

Question 9.
Zooplanktons come to the surface in day light and go to the bottom at night, this is–
(A) Circadian rhythm
(B) Diurnal rhythm
(C) Photoperiodism
(D) Phototactic movement
Answer:
(A) Circadian rhythm

Question 10.
Heliophytes are adapted to-
(A) Saline soil
(B) Saline water
(C) Bright sunlight
(D) Low sunlight
Answer:
(C) Bright sunlight

Question 11.
Population interaction is discussed under-
(A) Population level
(B) Community level
(C) Ecosystem level
(D) Individual level
Answer:
(B) Community level

Question 12.
Rate of metabolism increases in-
(A) Low temperature
(B) Higher temperature
(C) Low humidity
(D) High CO₂
Answer:
(C) Low humidity

Question 13.
A growing population shows-
(A) Low natality
(B) High mortality
(C) Low natality and emigration
(D) Low mortality and immigration
Answer:
(D) Low mortality and immigration

Question 14.
‘S’ shaped growth curve is seen in-
(A) Newly built ant population
(B) Stable human population
(C) Honeybee population
(D) Wasp population
Answer:
(B) Stable human population

Question 15.
High natality and immigration-
(A) Increase population size
(B) Decrease population size
(C) Do not change population size
(D) None of these
Answer:
(A) Increase population size

Question 16.
If B = Birth rate, N = Total number of individuals in a population and nb = Number of live birth, the equation for birth rate will be-
(A) N = nb / B
(B) B = nb / N
(C) B = N*nb
(D) B = N / nb
Answer:
(B) B = nb / N

Question 17.
Size of population remains unchanged if-
(A) Emigration = Immigration
(B) Natality > Mortality
(C) Immigration ≠ Emigration
(D) All of these
Answer:
(A) Emigration = Immigration

Question 18.
Population size decreases with-
(A) Emigration
(B) Immigration
(C) Low mortality
(D) High natality
Answer:
(A) Emigration

Question 19.
A positive inter-specific interaction is-
(A) Mutualism
(B) Parasitism
(C) Predation
(D) Cannibalism
Answer:
(A) Mutualism

Question 20.
Population size does not depend upon-
(A) Migration
(B) Natality
(C) Emigration
(D) Species interaction
Answer:
(D) Species interaction

Question 21.
High rate of predation results in-
(A) Decline in primary consumer
(B) Increase in primary consumer
(C) Decrease in higher level of consumer
(D) Decline in producer
Answer:
(A) Decline in primary consumer

Question 22.
In which of the following interactions, involved members keep very close contact?
(A) Competition
(B) Parasitism
(C) Predation
(D) None of these
Answer:
(B) Parasitism

Question 23.
What is ‘ + +’ interaction?
(A) Autotrophism
(B) Parasitism
(C) Symbiosis
(D) Predation
Answer:
(C) Symbiosis

Question 24.
Which of the following is a topographic factor of ecosystem?
(A) Brightness of light
(B) Wind speed
(C) Slope of hills
(D) Waves of sea
Answer:
(C) Slope of hills

Question 25.
Animals that maintain constant body temperature in any environment are called-
(A) Poikilothermic animals
(B) Homeothermic animals
(C) Eurythermal animals
(D) Stenothermal animals
Answer:
(B) Homeothermic animals

Question 26.
Example of stenothermal animals is-
(A) Birds
(B) Toads
(C) Ants
(D) Fishes
Answer:
(D) Fishes

Question 27.
Which of the following is an example of obligate parasite?
(A) Round worm
(B) Mosquito
(C) Louse
(D) Ticks
Answer:
(A) Round worm

Question 28.
Which of the following is not an abiotic factor?
(A) Water
(B) Soil
(C) Plants
(D) Air
Answer:
(C) Plants

Question 29.
Global ‘sink’ for CO₂ is-
(A) Tropical rain forest
(B) Mangrove
(C) Ocean
(D) Coral reef
Answer:
(C) Ocean

Question 30.
Which ecosystem has the highest primary productivity?
(A) Pond
(B) Ocean
(C) Desert
(D) Forest
Answer:
(B) Ocean

Question 31.
The most recently discovered ecosystem is-
(A) Vent*
(B) Crater
(C) Floating iceberg
(D) Coral reef
Answer:
(A) Vent*

Question 32.
Niche of a species is-
(A) Place of living
(B) Specific function
(C) Habitat and specific function
(D) None of these
Answer:
(C) Habitat and specific function

Question 33.
Which one of the following is mismatched?
(A) Deciduous forest : Shorea robusta
(B) Evergreen forest: Pinus roxburghii
(C) Xeric forest : Musa paradisica
(D) Mangrove forest : Barringtonia acutangula
Answer:
(C) Xeric forest : Musa paradisica

Question 34.
Insectivorous plants are-
(A) Organotrophs
(B) Autotrophs
(C) Heterotrophs
(D) Partial heterotrophs
Answer:
(D) Partial heterotrophs

Question 35.
Which of the following levels is not studied in synecology?
(A) Individual level
(B) Population level
(C) Community level
(D) Ecological level
Answer:
(A) Individual level

Question 36.
In ecology, interaction and organization among different organisms is studied in steps.
(A) 2
(B) 3
(C) 4
(D) 5
Answer:
(C) 4

Question 37.
Which of the following is a long day plant?
(A) Pea
(B) Cosmos
(C) Strawberry
(D) Dahlia
Answer:
(A) Pea

Question 38.
Which of the following is a short day plant?
(A) Pea
(B) Dahlia
(C) Clover
(D) Radish
Answer:
(B) Dahlia

Question 39.
Chlorophyll synthesis in plants is regulated by-
(A) Humidity
(B) Wind
(C) Temperature
(D) Light
Answer:
(D) Light

Question 40.
Melanin formation in human skin is regulated by-
(A) Humidity
(B) Light
(C) Temperature
(D) Pressure
Answer:
(B) Light

Question 41.
Migration of salmon, eel fish is regulated by-
(A) Water
(B) Humidity
(C) Temperature
(D) Light
Answer:
(C) Temperature

Question 42.
Temperature affects the size of an organism. This is known as-
(A) Bergmann’s rule
(B) Gloger’s rule
(C) Allen’s rule
(D) Lindeman law
Answer:
(A) Bergmann’s rule

Question 43.
Higher humidity makes the body colour of animals darker. This is known as-
(A) Bergmann’s rule
(B) Gloger’s rule
(C) Allen’s rule
(D) Lindeman law
Answer:
(B) Gloger’s rule

Question 44.
Animals of polar region have smaller pina, tail and limbs. This is known as-
(A) Bergmann’s rule
(B) Gloger’s rule
(C) Allen’s rule
(D) Lindeman law
Answer:
(C) Allen’s rule

Question 45.
The physiological reaction of organisms depending upon the length of day or night, is called-
(A) Photosynthesis
(B) Photoperiodism
(C) Photorespiration
(D) None of these
Answer:
(B) Photoperiodism

Question 46.
The act of leaving one’s native place permanently with the intent to reside somewhere else, is called-
(A) Adaptation
(B) Immigration
(C) Emigration
(D) Extinction
Answer:
(C) Emigration

Question 47.
Example of ‘+0’ interaction is-
(A) Autotrophism
(B) Mutualism
(C) Parasitism
(D) Commensalism
Answer:
(D) Commensalism

Question 48.
All the plant species of an ecosystem is collectively known as –
(A) Flora
(B) Fauna
(C) Biome
(D) Biomass
Answer:
(A) Flora

Question 49.
All the animal species of an ecosystem is collectively known as –
(A) Flora
(B) Fauna
(C) Biome
(D) Biomass
Answer:
(B) Fauna

Question 50.
In an ecosystem, energy flow is always-
(A) Unidirectional
(B) Bidirectional
(C) Tridirectional
(D) Multidirectional
Answer:
(A) Unidirectional

Question 51.
Number of trophic levels in a food chain ranges from-
(A) 14-16
(B) 11-13
(C) 7-10
(D) 3-5
Answer:
(D) 3-5

Question 52.
The percentage (%) of energy that flows to next tropic level in a food chain is-
(A) 100 %
(B) 10 %
(C) 20 %
(D) 90 %
Answer:
(B) 10 %

Question 53.
Lindeman law of energy flow through different trophic levels in an ecosystem is also known as-
(A) 5 % law
(B) 7 % law
(C) 10 % law
(D) 15 % law
Answer:
(C) 10 % law

Question 54.
Which of the following is a grazing food chain?
(A) Organic matter → Earthworm → Bacteria
(B) Plant → Human → Worm
(C) Decaying organic matter → Zooplankton → Small fish → Large fish
(D) Grass → Grasshopper → Frog → Snake → Hawk
Answer:
(D) Grass → Grasshopper → Frog → Snake → Hawk

Question 55.
Actively swimming aquatic organisms in a water body are called-
(A) Necton
(B) Benthos
(C) Plankton
(D) Neuston
Answer:
(A) Necton

Question 56.
Primary source of energy in an ecosystem is-
(A) Water
(B) Soil
(c) Air
(D) Sunlight
Answer:
(D) Sunlight

Question 57.
Food chain was scientifically described in 1966 by scientist-
(A) Tansley
(B) Lindeman
(C) Odum
(D) Haeckel
Answer:
(C) Odum

Question 58.
The community of organisms, that reside on or near the sea-bed is called-
(A) Necton
(B) Plankton
(C) Benthos
(D) Neuston
Answer:
(C) Benthos

Question 59.
The largest consumer population of marine ecosystem belongs to-
(A) Primary consumer
(B) Secondary consumer
(C) Tertiary consumer
(D) Topmost level of consumers
Answer:
(A) Primary consumer

Question 60.
Photoperiodism is a-
(A) Biochemical process
(B) Bio-physical process
(C) Physiological process
(D) All of these
Answer:
(C) Physiological process

Question 61.
Man is-
(A) Autotroph
(B) Omnivorous
(C) Carnivorous
(D) Herbivorous
Answer:
(B) Omnivorous

Question 62.
If different trophic levels are piled one upon another, we shall get-
(A) Food chain
(B) Food web
(C) Food pyramid
(D) Energy pyramid
Answer:
(C) Food pyramid

Question 63.
Which of the following is a component of macronutrient cycle?
(A) Na
(B) Mn
(C) Cu
(D) O₂
Answer:
(D) O₂

Question 64.
Which of the following is a component of micronutrient cycle?
(A) Cu
(B) C
(C) H₂
(D) O₂
Answer:
(A) Cu

Question 65.
Inhabitance of Anabaena in the leaf tissue of Azolla is an example of-
(A) Competition
(B) Predation
(C) Symbiosis
(D) Commensalism
Answer:
(C) Symbiosis

Question 66.
In an inter-specific relation, one of the two species is benefited but another one is neither benefited nor harmed. This interaction is called-
(A) Symbiosis
(B) Mutualism
(C) Commensalism
(D) Parasitism
Answer:
(C) Commensalism

Question 67.
Certain bacteria break organic molecules and return elementary components to nature. These bacteria are treated as-
(A) Decomposers
(B) Putrifying bacteria
(C) Transducers
(D) Transformers
Answer:
(D) Transformers

Question 68.
Unit of a population is-
(A) A community
(B) An animal species
(C) A plant species
(D) An individual of a species
Answer:
(D) An individual of a species

Question 69.
Unit of a community is-
(A) An individual of a species
(B) A plant species
(C) An animal species
(D) Population
Answer:
(D) Population

Question 70.
The largest population in an ecosystem is seen amongst-
(A) Decomposers
(B) Producers
(C) Primary consumers
(D) Secondary consumers
Answer:
(B) Producers

Fill in the blanks :

1. Group of organisms of same species is known as ______.
2. ______ rhythm is the daily rhythm of activities which is controlled by light.
3. Animal living in desert regions have few ______ glands.
4. Decomposers show ______ nutrition.
5. Inflow of bulk of animals into a population is called ______.
6. Interaction between flowers and insects is known as ______.
7. In predation, the animal which kills other animal to consume it, is called ______.
8. The step of food chain is called ______ level.
9. Energy flow is ______ -directional.
10. Birds of temperate region have ______ wings than that of tropical regions.
11. Organisms that break down organic molecules and return elementary components to nature, are called ______.
12. There are ______ types of food chain in an ecosystem.
13. Carbon cycle is a type of ______ cycle.
14. The sum total of the solar energy trapped by all producers is called ______ primary production.
15. Cyclical pool of carbon cycle involves the atmosphere and the ______.

Answer:

1. Population
2. Circadian
3. Sweat
4. Saprophytic
5. Immigration
6. Mutualism
7. Predator
8. Trophic
9. Uni Answers
10. Narrower
11. Transformers
12. Three
13. Nutrient
14. Gross
15. Seawater

State true or false :

1. Population is a bigger unit than community.
2. Light enhances the pigmentation of skin.
3. Poikilotherms can maintain constant body temperature.
4. Population size remains constant if birth rate is lower than death rate.
5. Migration is of two types.
6. Lichen is a type of obligatory mutualism.
7. Predation normally is an intraspecific interaction.
8. Parasitism is a negative-positive association.
9. Tapeworm is an ectoparasite.
10. Organic matters like protein, fat are biotic factors of an ecosystem.
11. Tertiary consumers are considered as decomposers.
12. Different food chains interconnect to form food web.
13. Only 0.02 % of the total energy, that comes to the earth from the sun, can be trapped.
14. Carbon bed of the lithosphere acts as reservoir pool for carbon.
15. Chemosynthetic micro-organisms are heterotrophs.

Answer:

1. False
2. True
3. False
4. False
5. True
6. True
7. False
8. True
9. False
10. False
11. False
12. True
13. True
14. True
15. False

Match the columns :

Question 1.

Left column	Right column
1. Short day plant	A. Rafflesia
2. Long day plant	B. Agaricus, Mucor
3. Day neutral plant	C. Dahlia, sugarcane
4. Heterotrophic plant	D. Pea, radish
	E. Tomato, cucumber

Answer:

Left column	Right column
1. Short day plant	C. Dahlia, sugarcane
2. Long day plant	D. Pea, radish
3. Day neutral plant	E. Tomato, cucumber
4. Heterotrophic plant	A. Rafflesia

Question 2.

Left column	Right column
1. Consumer	A. Tapeworm
2. Detritivore	B. Green plant
3. Producer	C. Human
4. Parasite	D. Earthworm
	E. Decaying leaves

Answer:

Left column	Right column
1. Consumer	C. Human
2. Detritivore	D. Earthworm
3. Producer	B. Green plant
4. Parasite	A. Tapeworm

Question 3.

Left column	Right column
1. Facultative mutualism	A. Orchid and mango tree
2. Symbiosis	B. Bug and human
3. Commensalism	C. Lichen
4. Predation	D. Insects and flowers
	E. Tiger and deer

Answer:

Left column	Right column
1. Facultative mutualism	D. Insects and flowers
2. Symbiosis	C. Lichen
3. Commensalism	A. Orchid and mango tree
4. Predation	E. Tiger and deer

Question 4.

Left column	Right column
1. Transducers	A. Bed bug
2. Ectoparasite	B. Green plants
3. Transformers	C. Plasmodium vivax
4. Endoparasite	D. Bacteria
	E. Lichen

Answer:

Left column	Right column
1. Transducers	B. Green plants
2. Ectoparasite	A. Bed bug
3. Transformers	D. Bacteria
4. Endoparasite	C. Plasmodium vivax

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 1.3A Classification of Diversity of Life: Taxonomy can serve as a valuable review tool before exams.

Classification of Diversity of Life: Taxonomy Class 9 WBBSE MCQ Questions

Multiple Choice Questions & Answers

Question 1.
The term ‘taxonomy’ was coined by-………………
A. John Ray
B. Linnaeus
C. Theophrastus
D. Augustin de Candolle
Answer:
D. Augustin de Candolle

Question 2.
Who is known as the ‘father of zoology’?
A. Aristotle
B. Theophrastus
C. Hippocrates
D. John Ray
Answer:
A. Aristotle

Question 3.
Who is known as the ‘father of taxonomy’?
A. Aristotle
B. Theophrastus
C. Augustin de Candolle
D. Linnaeus
Answer:
D. Linnaeus

Question 4.
Systematics is-………………
A. Nomenclature
B. Identification
C. Classification
D. All of these
Answer:
A. Nomenclature

Question 5.
The correct sequence of Linnaean hierarchy is-………………
A. Class-Phylum-Order-Family-Genus-Species
B. Phylum-Order-Class-Family-Genus-Species
C. Division-Class-Family-Order-Genus-Species
D. Division-Class-Order-Family-Genus-Species
Answer:
A. Class-Phylum-Order-Family-Genus-Species

Question 6.
‘Species’ was treated as a unit of classification by-………………
A. John Ray
B. Linnaeus
C. Huxley
D. Augustin de Candolle
Answer:
A. John Ray

Question 7.
Which of the following are categories of taxonomic hierarchy?
A. Family
B. Order
C. Genus
D. All of these
Answer:
D. All of these

Question 8.
Hierarchy in classification was proposed by-………………
A. Simpson
B. Linnaeus
C. Mayer
D. Hutchinson
Answer:
B. Linnaeus

Question 9.
Which of the following is a taxonomic rank?
A. Mammalia
B. Animalia
C. Class
D. Plantae
Answer:
C. Class

Question 10.
Number of taxa in taxonomic hierarchy is-………………
A. 27
B. 7
C. 17
D. 9
Answer:
B. 7

Question 11.
Full form of ICBN is-………………
A. International Classification of Biological Nomenclature
B. International Code of Botanical Nomenclature
C. International Code of Biological Nomenclature
D. International Class of Biological Nomenclature
Answer:
B. International Code of Botanical Nomenclature

Question 12.
The first and second word in a binomial nomenclature respectively indicates-………………
A. Genus and species
B. Species and genus
C. Family and genus
D. Family and species
Answer:
A. Genus and species

Question 13.
Scientific names of paddy plant and pea plant respectively are-………………
A. Pisum sativum and Oryza sativa
B. Oryza sativa and Plsum sativum
C. Triticum aestivum and Pisum sativum
D. Zea mays and Pisum sativum
Answer:
B. Oryza sativa and Plsum sativum

Question 14.
Which of the following covers highest number of organisms?
A. Species
B. Family
C. Class
D. Phylum
Answer:
D. Phylum

Question 15.
The scientific name of human should be correctly printed as-………………
A. Homo sapiens
B. Homosapiens sapiens
C. Homo Sapiens Sapiens
D. Homo sapiens sapiens
Answer:
D. Homo sapiens sapiens

Question 16.
Which of the following is not in a correct hierarchical order?
A. Class-Order-Family
B. Family-Order-Class
C. Order-Family-Genus
D. Phylum-Class-Order
Answer:
B. Family-Order-Class

Question 17.
Binomial nomenclature is-………………
A. A scientific name comprising of a generic and a specific epithet
B. A Latin name
C. Scientific name given to a plant
D. One name given by two different scientists
Answer:
A. A scientific name comprising of a generic and a specific epithet

Question 18.
Binomial nomenclature was first published in the book-………………
A. Systema Naturae
B. Genera Plantarum
C. Species Plantarum
D. The Plants
Answer:
C. Species Plantarum

Question 19.
Scientific name of India’s national bird is-………………
A. Passer domesticus
B. Corvus splendens
C. Pavo cristatus
D. Columba livia
Answer:
C. Pavo cristatus

Question 20.
Naturally interbreeding animals belong to the same-………………
A. Family
B. Class
C. Genus
D. Species
Answer:
D. Species

Question 21.
The author of the book ‘Systema Naturae’ is-…………………
A. Aristotle
B. John Ray
C. Linnaeus
D. Theophrastus
Answer:
C. Linnaeus

Fill in the blanks:

1. ……………. is known as the ‘father of botany’.
2. The smallest unit of classification is ……………
3. The concept of ‘binomial nomenclature’ was proposed by ……………..
4. A family comprises of related ……………..
5. The theoretical study of classification is known as ……………..
6. ICBN is the set of rules and recommendations used for naming ……………..
7. The highest rank of taxonomic hierarchy is called ……………..
Answer:
1. Theophrastus
3. Linnaeus
5. Taxonomy
7. Kingdom
2. Species
4. Genera
6. Plants

State True or False

1. Human beings belong to the kingdom Animalia. — True
2. The book ‘Species Plantarum’ was written by Augustin de Candolle. — False
3. Panthera tigris is the scientific name of India’s national animal. — True
4. Order is a category in Linnaean hierarchy. — True
5. Linnaean hierarchy consisted of 10 categories. — False
6. The category ‘division’ is used during the classification of plants. — True

Match the columns

Left column	Right column
1. Peacock	A. Panthera leo
2. Lion	B. Pavo cristatus
3. Mango	C. Pisum sativum
4. Pea	D. Mangifera indica
	E. Homo sapiens

Answer:
1-B; 2-A; 3-D; 4-C

Left column	Right column
1. Kingdom	A. Dicotyledoneae
2. Division	B. Mangifera
3. Class	C. Angiospermae
4. Genus	B. Sapindales
	E. Piantae

Answer:
1-E; 2-C; 3-A; 4-B

Left column	Right column
1. Cyanogen theory	A. Lamarck
2. Systematics	B. de Candolle
3. Taxonomy	C. Pfluger
4. Biology	B. Oparin
	E. Linnaeus

Answer:
1-С; 2-Е; 3-B; 4-A

Left column	Right column
1, Concept of species	A. Bentham and Hooker
2. Binomial nomenclature	B. Ernst Mayr
3. Modern definition of species	C. John Ray
4. Genera Plantarum	D. Linnaeus
	E. Darwin

Answer:
1-C; 2-D; 3-B; 4-A

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 1.2 Biology and its Branches can serve as a valuable review tool before exams.

Biology and its Branches Class 9 WBBSE MCQ Questions

Multiple Choice Questions & Answers

Question 1.
The branch of science that deals with the study of structures and life processes of living forms is called-………….
A. Psychology
B. Geology
C. Biology
D. Chemistry
Answer:
C. Biology

Question 2.
The Greek word ‘Bios’ means-………….
A. Life
B. Organism
C. Organic
D. Microbes
Answer:
A. Life

Question 3.
Among the following, the oldest branch of biology is-………….
A. Cytology
B. Taxonomy
C. Histology
D. Ecology
Answer:
B. Taxonomy

Question 4.
Astrobiology or exobiology is a science which is developed by the combination of-………….
A. Biology and electronics
B. Biology and space science
C. Biology and astrology
D. Biology and computer science
Answer:
B. Biology and space science

Question 5.
The branch of biology that deals with the study of different types of tissues is -………….
A. Histology
B. Pathology
C. Ethology
D. Ecology
Answer:
A. Histology

Question 6.
The branch of biology that deals with the study of interactions between living organisms and the environment is-………….
A. Pathology
B. Ethology
C. Ecology
D. Embryology
Answer:
C. Ecology

Question 7.
The branch of science that deals with the study of different diseases and their causes is-………….
A. Ethology
B. Anatomy
C. Pathology
D. Physiology
Answer:
C. Pathology

Question 8.
The study of structure and development of embryo, is known as-………….
A. Palaeontology
B. Ecology
C. Physiology
D. None of these
Answer:
D. None of these

Question 9.
Physiology is the study of-………….
A. Different functional activities and life processes of an organism
B. Physical ability of an organism
C. Physical structure of an organism
D. Genes and its behaviour
Answer:
A. Different functional activities and life processes of an organism

Question 10.
Palaeontology is the study of-………….
A. Fossils
B. Embryos
C. Primitive plants
D. Primitive animals
Answer:
A. Fossils

Question 11.
The study of those animals, which cause harm to other organisms by drawing nutrients from them, is known as-………….
A. Cytology
B. Parasitology
C. Palaeontology
D. Entomology
Answer:
B. Parasitology

Question 12.
The term ‘biology’ was coined by-………….
A. Lamarck
B. Oparin
C. Linnaeus
D. Huxley
Answer:
A. Lamarck

Question 13.
The branch of classical biology that deals with the study of different forms of life, their classification and naming, is known as-………….
A. Genetics
B. Cytology
C. Histology
D. Taxonomy
Answer:
D. Taxonomy

Question 14.
The branch of biology that deals with the study of plants, is called-………….
A. Zoology
B. Botany
C. Agriculture
D. Horticulture
Answer:
B. Botany

Question 15.
Zoology is the study of-………….
A. Zoos
B. Birds
C. Mammals
D. Animals
Answer:
D. Animals

Question 16.
Biometry is a branch of science, which is developed by the combination of biology, mathematics and-………….
A. Trigonometry
B. Geometry
C. Statistics
D. Electronics
Answer:
C. Statistics

Question 17.
The branch of biology developed by the combination of biology and electronics is-………….
A. Bionics
B. Biometry
C. Cybernetics
D. Biophysics
Answer:
A. Bionics

Question 18.
The branch of biology that deals with the study of different aspects of cell, is known as-………….
A. Histology
B. Cytology
C. Physiology
D. Psychology
Answer:
B. Cytology

Question 19.
Study of humankind under the light of geography, sociology and palaeontology, is known as-………….
A. Geology
B. Anthropology
C. Human physiology
D. Human anatomy
Answer:
B. Anthropology

Question 20.
Study of physiology of organisms in outer space, is known as-………….
A. Exobiology
B. Space science
C. Astronomy
D. Astrology
Answer:
A. Exobiology

Question 21.
Immunology is the branch of science that deals with-………….
A. Body’s own defence against infection
B. Action of hormone in the body
C. Action of medicines in the body
D. Action of toxins in the body
Answer:
A. Body’s own defence against infection

Question 22.
Oceanography is an inter-disciplinary science, that mainly deals with-…………..
A. Coastal geography and phycology
B. Marine science and robotics
C. Oceanic geology and marine biology
D. Aquatic biology and meteorology
Answer:
C. Oceanic geology and marine biology

Fill in the blanks:

1. Study of fungi is known as ………………
2. Ethology is the study of ……………… of organisms.
3. ………………deals with the study of crude drugs.
4. The scientific study of production of flowers and ornamental plants is known as……………….
5. The knowledge of is ……………. utilised to make different instruments like endoscope, microscope, etc.
6. Palaeontology is the science which is formed by the combination of biology and …………….
Answer:
1. Mycology
2. Behaviour
3. Pharmacognosy
4. Floriculture
5. Bionics
6. Geology

State True or False

1. Taxonomy is the oldest branch of biology. — True
2. Bio informatics is the branch of science which is a combination of biology and electronics. — False
3. Sericulture is a branch of applied biology. — True
4. Knowledge of microbiology is important for the production of antibiotics. — True
5. Knowledge of biology can be utilized to control population explotion. — True
6. Study of human behaviour is called thanatology. — False

Match the columns

Left column	Right column
1. Apiculture	A. Oysters
2. Pisciculture	B. Honeybees
3. Sericulture	C. Birds
4. Pearl culture	D. Fishes
	E. Silkworms

Answer:
1-B; 2-D; 3-E; 4-A

Left column	Right column
1. Anthropology	A. Study of genes
2. Cytology	B. Study of humankind
3. Genetics	C. Study of fossils
4. Palaeontology	D. Study of cells
	E. Study of embryo

Answer:
1-B; 2-D; 3-A; 4-C

Left column	Right column
1. Study of biomolecules	A. Naked gene
2. Response to stimuli	B. Microbiology
3. Study of microorganisms	C. Mimosa pudica
3. Study of microorganisms	C. Mimosa pudica

Answer:
1-E; 2-C; 3-B; 4-D

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 5.2 Natural Resources and its Sustainable Use can serve as a valuable review tool before exams.

Natural Resources and its Sustainable Use Class 9 WBBSE MCQ Questions

Multiple Choice Questions :

Question 1.
The concept, which supports that conservation of environment and development of economy must go on parallely, is called-
(A) Human development
(B) Sustainable development
(C) Industrial development
(D) Unidirectional development
Answer:
(B) Sustainable development

Question 2.
A natural resource, which may be replenished is-
(A) Coal
(B) Forest
(C) Petroleum
(D) Natural gas
Answer:
(B) Forest

Question 3.
A non-renewabie natural resource is-
(A) Coal
(B) Solar energy
(C) Water
(D) Wood
Answer:
(A) Coal

Question 4.
Trees of a forest continuously provide us-
(A) Furniture
(B) Oxygen
(C) Coal
(D) Wood
Answer:
(B) Oxygen

Question 5.
Most of the members of a forest are-
(A) Producers
(B) Decomposers
(C) Primary Consumers
(D) Secondary consumers
Answer:
(A) Producers

Question 6.
A forest cannot be used for-
(A) Pisciculture
(B) Apiculture
(C) Harvesting medicinal plants
(D) Ecotourism
Answer:
(A) Pisciculture

Question 7.
Which is not a cause of deforestation?
(A) Expansion of cultivation
(B) Forest fire
(C) Flood
(D) Industrial development
Answer:
(C) Flood

Question 8.
Sudden deforestation in an area may be due to-
(A) Expansion of cultivation
(B) Industrial expansion
(C) Laying railway track
(D) Forest fire
Answer:
(D) Forest fire

Question 9.
Production of prawn is a practice of-
(A) Epiculture
(B) Horticulture
(C) Pisciculture
(D) Lac culture
Answer:
(C) Pisciculture

Question 10.
A conventional source of energy is-
(A) Sunlight
(B) Petroleum
(C) Wind
(D) All of these
Answer:
(B) Petroleum

Question 11.
A non-conventional source of energy is-
(A) Coal
(B) Natural gas
(C) Petroleum
(D) Wind
Answer:
(D) Wind

Question 12.
Which of the following has a role in food production?
(A) Lac culture
(B) Agriculture
(C) Pearl culture
(D) None of these
Answer:
(A) Lac culture

Question 13.
Which part of forest trees prevents soil erosion?
(A) Shoot
(B) Root
(C) Root and shoot
(D) Stem
Answer:
(B) Root

Question 14.
Coal is used mostly in-
(A) Cooking
(B) Running rail engine
(C) Steel industry
(D) Thermal power plants
Answer:
(D) Thermal power plants

Question 15.
A renewable natural resource is-
(A) Livestock
(B) Natural gas
(C) Petroleum
(D) None of these
Answer:
(A) Livestock

Question 16.
Deforestation causes-
(A) Soil erosion
(B) Global warming
(C) Drought
(D) All of these
Answer:
(D) All of these

Question 17.
The method of water conservation is-
(A) Plantation
(B) Rain water harvesting
(C) Digging water pits
(D) All of these
Answer:
(D) All of these

Question 18.
Source of Vitamin C and amino acid is-
(A) Sago
(B) Yam bean
(C) Moringa oleifera
(D) Gum arabic
Answer:
(C) Moringa oleifera

Question 19.
Which appliance does help in conservation of energy?
(A) Refrigerator
(B) Solar water heater
(C) Computer
(D) Air purifier
Answer:
(B) Solar water heater

Question 20.
One of the non-human causes of deforestation is-
(A) Expansion of grazing land
(B) Expansion of cultivating land
(C) Industrial expansion
(D) Forest fire
Answer:
(D) Forest fire

Question 21.
Main problem for Indian rivers is-
(A) Water scarcity
(B) Silting
(C) Low water current
(D) Pollution
Answer:
(D) Pollution

Question 22.
The World summit on ‘Fight against hunger’, organised by United Nation’s Food and Agriculture Organisation was held in Rome in-
(A) 1996
(B) 1999
(C) 2003
(D) 2006
Answer:
(A) 1996

Question 23.
Pisciculture deals with-
(A) Culture of mushroom
(B) Culture of poultry birds
(C) Culture of prawn
(D) Culture of fish
Answer:
(D) Culture of fish

Question 24.
Source of fruits and vegetables is-
(A) Horticulture
(B) Floriculture
(C) Apiculture
(D) Pisciculture
Answer:
(A) Horticulture

Question 25.
Most modern concept of environmental development is-
(A) Urbanization
(B) Sustainable development
(C) Control of industrialisation
(D) Deforestation
Answer:
(B) Sustainable development

Question 26.
Social development, economical development and ecological development are the three basic steps of-
(A) Human development
(B) Industrial development
(C) Sustainable development
(D) Unidirectional development
Answer:
(C) Sustainable development

Question 27.
Most of the forests in India are of type.
(A) Deciduous
(B) Evergreen
(C) Coniferous
(D) Mangrove
Answer:
(A) Deciduous

Question 28.
The type of forest, which has most economic utility is-
(A) Deciduous
(B) Evergreen
(C) Coniferous
(D) Mangrove
Answer:
(C) Coniferous

Question 29.
Which of the following does not occur due to forestation?
(A) Water cycle regulation
(B) Acid rain
(C) Flood control
(D) Climate regulation
Answer:
(B) Acid rain

Question 30.
Which of the following is a cause of deforestation?
(A) Excess agriculture
(B) Excess industry
(C) Urbanisation
(D) All of these
Answer:
(D) All of these

Question 31.
Which of the following should be done before cutting a tree?
(A) At least three similar trees should be planted
(B) Appoint skilled workers for cutting trees
(C) Marking other trees to be cut
(D) Plan to sell those cut trees
Answer:
(A) At least three similar trees should be planted

Question 32.
Which of the following is not a function of forest?
(A) Maintaining O₂ – CO₂ balance
(B) Reduction of soil erosion
(C) Reduction of rainfall
(D) Food and wood production
Answer:
(C) Reduction of rainfall

Question 33.
The combined mass of water found in all water bodies on earth, is called-
(A) Atmosphere
(B) Hydrosphere
(C) Lithosphere
(D) Biosphere
Answer:
(B) Hydrosphere

Question 34.
Which of the following should not be present in drinking water?
(A) Magnesium
(B) Soluble CO₂
(C) Sodium salt
(D) Harmful bacteria
Answer:
(D) Harmful bacteria

Question 35.
Which of the following step should be taken for reducing wastage of water?
(A) Store water at the earliest
(B) Stop unnecessary use of water
(C) Prevent water pollution
(D) All of these
Answer:
(D) All of these

Question 36.
Rain water is not always safe for household purpose because of-
(A) Absence of mineral salts
(B) Presence of organic acid
(C) Presence of few protozoa
(D) Presence of inorganic acid
Answer:
(D) Presence of inorganic acid

Question 37.
Use of which of the following reduces use of fossil fuels?
(A) Solar car
(B) Microwave oven
(C) Biofuels
(D) All of these
Answer:
(D) All of these

Question 38.
Pearl culture is a type of-
(A) Tissue culture
(B) Apiculture
(C) Horticulture
(D) Mariculture
Answer:
(D) Mariculture

Question 39.
Growing and cultivation of trees is termed as –
(A) Silviculture
(B) Horticulture
(C) Tissue culture
(D) Floriculture
Answer:
(A) Silviculture

Question 40.
Example of an alternative food source is-
(A) Rice
(B) Pulse
(C) Meat
(D) Single cell protein
Answer:
(D) Single cell protein

Question 41.
Which of the following is not associated with food production?
(A) Horticulture
(B) Agriculture
(C) Pisciculture
(D) Pearl culture
Answer:
(D) Pearl culture

Question 42.
An example of fossil fuel is-
(A) Wood
(B) Coal
(C) Uranium
(D) Both (A) (B)
Answer:
(B) Coal

Question 43.
In which of the following countries, utilization of energy is not increasing any more?
(A) America
(B) India
(C) Bangladesh
(D) China
Answer:
(A) America

Question 44.
Which of the following is a cause of food crisis?
(A) Change in climate
(B) Natural calamities
(C) Population explosion
(D) All of these
Answer:
(D) All of these

Fill in the blanks :

1. The litter on the forest floor, is partly decomposed to form sticky _____.
2. _____ is used to prepare chewing gum.
3. _____ is the main economically important product of forest.
4. Rain water has a slightly _____ pH.
5. Sago is extracted from _____ trees.
6. Coal, petroleum, natural gas are the conventional sources for _____ power.
7. _____ by trees increases humidity of air.
8. _____ is the conventional source for hydel power.

Answer:

1. Humus
2. Gum arabic
3. Timber
4. Acidic
5. Palm
6. Thermal
7. Transpiration
8. Water

State true or false :

1. Ecotourism is a productive aspect of forest, from which government earns huge amount of money.
2. Due to deforestation, concentration of greenhouse gases increases in the atmosphere.
3. Fossil fuels are renewable sources of energy.
4. Rain water is generally free from germs and contaminants.
5. Sago is a protein-rich matter.
6. Rain water harvesting is practiced in areas with excessive suspended particulate matters in air.
7. Afforestation helps to reduce soil erosion.
8. Fossil fuels include coal and natural gas only.
9. Coal, natural gas, firewood are examples of non-conventional energy sources.
10. Forestation along the slope of watershed reduces the deposition silt in riverbed.

Answer:

1. True
2. True
3. False
4. True
5. False
6. False
7. True
8. False
9. False
10. True

Match the columns :

Question 1.

Left column	Right column
1. Local use of forest	A. Flood and drought
2. Cause of deforestation	B. Ecotourism
3. Result of deforestation	C. Honey, timber
4. Productive use of forest	D. Rain water harvesting
	E. Urbanisation

Answer:

Left column	Right column
1. Local use of forest	C. Honey, timber
2. Cause of deforestation	E. Urbanisation
3. Result of deforestation	A. Flood and drought
4. Productive use of forest	B. Ecotourism

Question 2.

Left column	Right column
1. Non conventional energy sourc	A. Vegetables, spices
2. Poultry	B. Yam bean, sago
3. Horticulture	C. Eggs, meat
4. Alternative food source	D. Coal, kerosene oil
	E. Geothermal energy

Answer:

Left column	Right column
1. Non conventional energy sourc	E. Geothermal energy
2. Poultry	C. Eggs, meat
3. Horticulture	A. Vegetables, spices
4. Alternative food source	B. Yam bean, sago

Well structured WBBSE Class 9 Life Science MCQ Questions Chapter 1.1 Basic Properties of Life can serve as a valuable review tool before exams.

Basic Properties of Life Class 9 WBBSE MCQ Questions

Multiple Choice Questions & Answers

Question 1.
One of the basic properties of a living organism is- …………………….
A. To intake oxygen
B. To move
C. To reproduce
D. To absorb water
Answer:
A. To intake oxygen

Question 2.
All reactions of life take place within the- …………………….
A. Nucleus
B. Mitochondrion
C. Chromosome
D. Protoplasm
Answer:
D. Protoplasm

Question 3.
All the biochemical processes occurring within a living organism in order to sustain life, are collectively known as- …………………….
A. Energy
B. Metabolism
C. Nutrition
D. Digestion
Answer:
B. Metabolism

Question 4.
The concept of spontaneous generation of life was first proposed by- …………………….
A. Haldane and Oparin
B. Aristotle
C. Urey and Miller
D. Melvin Calvin
Answer:
B. Aristotle

Question 5.
The concept of origin of life from inorganic matter is known as-…………………….
A. Special creation
B. Chemosynthesis
C. Biogenetic concept
D. Pangenesis
Answer:
B. Chemosynthesis

Question 6.
The first step of chemical origin of life was the-…………………….
A. Origin of coacervates
B. Origin of complex organic compounds
C. Origin of simple organic compounds
D. Origin of proteinoids
Answer:
C. Origin of simple organic compounds

Question 7.
The essential gaseous ingredient of present atmosphere, which was absent in the primitive atmosphere before the origin of life, is-…………………….
A. Carbon dioxide
B. Nitrogen
C. Oxygen
D. Carbon monoxide
Answer:
C. Oxygen

Question 8.
The concept of chemosynthesis of life on earth was proposed by-…………………….
A. Aristotie
B. Miller and Urey
C. Oparin and Haldane
D. Sidney Fox
Answer:
C. Oparin and Haldane

Question 9.
According to Cosmozoic theory or Panspermia, the reason of origin of life is-…………………….
A. Extraterrestrial objects, such as comet
B. Biochemical reactions
C. Spontaneous creation
D. None of these
Answer:
A. Extraterrestrial objects, such as comet

Question 10.
The simple compound present in the primitive earth, was-…………………….
A. H₂O
B. NH₃
C. CH₄
D. All of these
Answer:
D. All of these

Question 11.
The simple organic matter produced from the inorganic compounds during chemosynthesis of life was-…….
A. Fatty acids
B. Amino acids
C. Both A& B.
D. None of these
Answer:
C. Both A& B.

Question 12.
Coacervate, as proposed by Oparin, was mainly composed of-…………………….
A. Lipids
B. Proteins
C. Carbohydrates
D. All of these
Answer:
A. Lipids

Question 13.
‘Hot dilute soup’ produced in the primitive ocean contained-…………………….
A. Amino acids and fatty acids
B. Purines and pyrimidines
C. Simple sugars
D. All of these
Answer:
D. All of these

Question 14.
Formation of proteinoids, before the origin of primordial cell, was explained by-…………………….
A. A I Oparin
B. J B S Haldane
C. Stanley Miller
D. Sidney Fox
Answer:
D. Sidney Fox

Question 15.
The term ‘biodiversity’ was coined by-…………………….
A. Norman Myers
B. Alexander Oparin
C. Gaylord Nelson
D. W G Rosen
Answer:
D. W G Rosen

Question 16.
In the laboratory experiment of chemosynthesis of organic matters from simple inorganic compounds, Urey and Miller used-…………………….
A. NH_{3 ,}CH₄ ,H₂O
B. H₂O, NH₃,CH₄, H₂
C. NH₃, CH₄, H₂O, O₂
D. All of these
Answer:
B. H₂O, NH₃,CH₄, H₂

Question 17.
The energy required for the chemical reactions, which occur during chemosynthesis of life, was obtained from-…………………….
A. Extreme heat of the primitive earth
B. Cosmic rays
C. Lightning
D. All of these
Answer:
D. All of these

Question 18.
In primitive ocean, proteinoids were formed by polymerisation of-…………………….
A. Sugar molecules
B. Fatty acids
C. Nucleic acids
D. Protein molecules
Answer:
D. Protein molecules

Question 19.
The basic physical component of life is-…………………….
A. Nucleic acid
B. Glycerol
C. Glucose
D. Nucleoside
Answer:
A. Nucleic acid

Question 20.
Protobionts are-…………………….
A. A cluster of microsphere molecules, surrounded by a membrane
B. A cluster of protein molecules, surrounded by a lipid layer
C. A cluster of proteinoids, covered with a limiting membrane
D. Nothing but protocells
Answer:
D. Nothing but protocells

Question 21.
The first phase of chemical reactions during chemosynthesis of organic matters started in-…………………….
A. Atmosphere
B. Primitive ocean
C. Earth’s surface
D. Beneath earth’s crust
Answer:
A. Atmosphere

Question 22.
During origin of life, the atmosphere of earth was-…………………….
A. Oxidising
B. Reducing
C. Partially oxidised and partially reduced
D. None of these
Answer:
B. Reducing

Question 23.
The ‘Cyanogen hypothesis’ was given by-…………………….
A. Pfluger
B. Daniken
C. Miller
D. Arrhenius
Answer:
A. Pfluger

Question 24.
Origin of life on the earth was manifested by the formation of-…………………….
A. Microspheres
B. Proteinoids
C. Nucleic acids
D. Protobionts
Answer:
D. Protobionts

Question 25.
Life on the earth originated about-…………………….
A. 2.5 billion years back
B. 4.4 billion years back
C. 3.7 million years back
D. 4.5 million years back
Answer:
B. 4.4 billion years back

Question 26.
The main role played by the organisms in transforming the de-oxidised atmosphere of the primitive earth into an oxidising one, are-…………………….
A. Green plants
B. Photosynthetic bacteria
C. Algae
D. Cyanobacteria
Answer:
D. Cyanobacteria

Question 27.
According to Sidney Fox, prior to the origin of life, numerous thin membrane-bound proteinoid-clusters were termed as-…………………….
A. Coacervates
B. Microspheres
C. Protocells
D. Protobionts
Answer:
B. Microspheres

Question 28.
The relentless effort of a living organism to adjust itself with the changing environment, is called-…………………….
A. Adaptation
B. Migration
C. Evolution
D. Natural selection
Answer:
A. Adaptation

Question 29.
Mutation in organisms occurs-…………………….
A. Slow and steadily
B. With the change in nature
C. Suddenly and temporarily
D. Suddenly and permanently
Answer:
D. Suddenly and permanently

Question 30.
The assumed temperature of the earth during its origin was about-…………………….
A. 2000°-3000°C
B. 3000°-4000°C
C. 400°-500°C
D. 5000°-6000°C
Answer:
D. 5000°-6000°C

Question 31.
The ‘Ancient Astronauts’ hypothesis of origin of life was proposed by scientist-…………………….
A. Pfluger
B. Pasteur
C. Urey
D. Daniken
Answer:
D. Daniken

Question 32.
The physical basis of life is-…………………….
A. Cell
B. Endoplasm
C. Protoplasm
D. Cytoplasm
Answer:
C. Protoplasm

Question 33.
‘Naked gene’ is not covered by-…………………….
A. Plasma membrane
B. Lipid membrane
C. Peptidoglycan membrane
D. Nuclear membrane
Answer:
D. Nuclear membrane

Fill in the blanks:

1. The first nucleic acid which originated on earth was …………….
Answer: RNA

2. The country with the richest biodiversity on earth, is …………….
Answer: Brazil

3. Eye colour is an example of ……………. variation.
Answer: Discontinuous

4. The earliest photosynthetic living organism on this earth was …………….
Answer: Cyanobacteria

5. The concept of spontaneous generation of life was rejected by …………….
Answer: Pasteur

6. ……………. and nucleic acid combined together to form life on primitive earth.
Answer: Protein

7. ……………. is responsible for discontinuous variation.
Answer: Mutation

8. Proteinoid molecules conjugate to form …………….
Answer: Microspheres

State True or False

1. Adaptability is the ability of a living organism to adjust with the changing environment. — True
2. Biogenesis is a synonym of biopoiesis. — False
3. Scientist Haldane coined the term ‘primordial soup’. — False
4. Hydrogen was the predominant gas in the primitive atmosphere. — True
5. Mimosa pudica respond to stimulus. — True
6. Alpha diversity is called turnover diversity. — False

Match the columns

Left column	Right column
1. Biochemical theory of life	A. Aristotle
2. Microsphere	B. Oparin
3. Spontaneous generation	C. Haldane
4. Hot dilute soup	D. Stanley Miller
	E. Sidney fox

Answer:
1-B; 2-E; 3-A; 4-C

Left column	Right column
1. Human weight	A. Beta diversity
2. Species richness in an area	B. Discontinuous variation
3. Turnover diversity	C. Gamma diversity
4. Human eye colour	D. Alpha diversity
	E. Continuous variation

Answer:
1-E; 2-D; 3-A; 4-B

 

Detailed explanations in West Bengal Board Class 9 Life Science Book Solutions Chapter 3.2A Respiration: Organ-Level Respiration offer valuable context and analysis.

WBBSE Class 9 Science Chapter 3.2A Question Answer – Respiration: Organ-Level Respiration

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

Question 1.
Which physiological process provides energy to perform life activities?
Answer:
Respiration provides energy to perform life activities.

Question 2.
Which typical respiratory organ is seen in halophytic plants?
Answer:
Pneumatophore or breathing root is the typical respiratory organ of the halophytic plants.

Question 3.
Name two organisms, which exchange respiratory gases through body surface.
Answer:
Amoeba and Hydra exchange respiratory gases through body surface.

Question 4.
Name two invertebrates, which perform organ-level respiration by skin.
Answer:
Earthworms and leeches are two invertebrates which perform organ-level respiration by skin.

Question 5.
Name two invertebrates, which perform organ-level respiration by gills.
Answer:
Crabs and prawns perform organ-level respiration by gills.

Question 6.
Name a vertebrate, which is capable of performing organ-level respiration by skin.
Answer:
Frogs are capable of performing organ-level respiration through skin.

Question 7.
Which parts of gills act as the site of gaseous exchange?
Answer:
Gill lamellae act as the site of gaseous exchange.

Question 8.
Which part of lungs act as the site of gaseous exchange?
Answer:
Alveoli of lungs act as the site of gaseous exchange.

Question 9.
Mention a common feature of gill lamellae and alveoli of lungs.
Answer:
Both gill lamellae and alveoli of lungs are well vascularised.

Question 10.
Name two parts of the human respiratory system, which do not take part in gaseous exchange?
Answer:
Trachea and bronchioles do not take part in gaseous exchange.

Question 11.
Through which opening, air enters into the trachea from pharynx?
Answer:
Air enters into the trachea from pharynx through an opening, called glottis.

Question 12.
Where is larynx located?
Answer:
Larynx is located at the upper end of the trachea.

Question 13.
Where is bronchus located?
Answer:
Bronchus is located at the lower end of the trachea.

Question 14.
Which bony structure holds the gill lamellae in fishes?
Answer:
In fishes, the gill lamellae are held by bony gill arch.

Question 15.
Which bony plate covers the gill chamber of bony fishes?
Answer:
Operculum covers the gill chamber of bony fishes.

Question 16.
Which fine tubular structures supply air directly to the cells in the body of insects?
Answer:
Tracheoles supply air directly to the cells in the body of insects.

Question 17.
How much air does a healthy adult human inhale or exhale during normal breathing?
Answer:
A healthy adult human inhales or exhales 500 ml of air during normal breathing.

Question 18.
What is the maximum volume of air, which a healthy adult human can hold in the lungs?
Answer:
A healthy adult human can hold a maximum of 4500-5000 \mathrm{ml} of air in the lungs.

Question 19.
How can a person increase the vital capacity of the lungs?
Answer:
A person can increase the vital capacity of the lungs by performing breathing exercises or ‘pranayam’.

Question 20.
Mention two very common diseases caused due to smoking.
Answer:
Smoking causes emphysema and COPD (Chronic Obstructive Pulmonary Disease).

Question 21.
Name the flattened sheet of respiratory muscle, which separates the thoracic cavity from the abdominal cavity.
Answer:
The flattened sheet of respiratory muscle which separates the thoracic cavity from abdominal cavity, is called diaphragm.

Question 22.
Which typical structure prevents the entry of food particles into the larynx?
Answer:
A cartilaginous valve, called epiglottis, prevents entry of food particles into the larynx.

Question 23.
Which structures prevent flattening of trachea during exhalation?
Answer:
There are 16 to 20 half ring-like cartilaginous structures, fitted anteriorly to the trachea, which prevent its flattening during exhalation.

Question 24.
What is the accessory respiratory organ of Koi fish called?
Answer:
The accessory respiratory organ of Koi fish is called labyrinth organ.

Question 25.
Name two muscles of human body, which help in breathing.
Answer:
Intercostal muscles and muscular diaphragm of human body help in breathing.

Question 26.
Name the two parts of pleura.
Answer:
The outer part of pleura is called parietal pleura, and the inner part of pleura is called visceral pleura.

Question 27.
Name a respiratory pigment of vertebrates.
Answer:
A respiratory pigment of vertebrates is haemoglobin.

Question 28.
Name a respiratory pigment of invertebrates.
Answer:
A respiratory pigment of invertebrates is haemocyanin.

Question 29.
When do frogs respire through their skin?
Answer:
Frogs respire through their skin during hibernation (i.e. winter sleep).

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

Question 1.
What is meant by organ-level respiration?
Answer:
The physical process involving the intake of oxygen in the body and release of carbon dioxide from the body, with the help of typical respiratory organs, is known as organ-level respiration.

Question 2.
How do unicellular organisms perform organlevel respiration?
Answer:
Unicellular organisms do not possess organs, therefore they do not perform organ-level respiration, but perform gaseous exchange of O₂ and CO₂ by diffusion through cell membrane.

Question 3.
How do sponges and jellyfishes perform organ-level respiration without respiratory organ?
Sponges and jellyfishes do not have any respiratory organ. Their body cells perform gaseous exchange by diffusion through respective cell membranes. This is how they perform organlevel respiration.

Question 4.
How does the skin of earthworm act as a respiratory organ?
Answer:
The skin of earthworm always remain moist. Atmospheric oxygen is dissolved in the film of fluid over the skin surface. By diffusion, this gas gets mixed in the blood of the capillaries below the skin. Blood plasma of earthworm contains haemoglobin, which receives oxygen and carries it to different parts of the body. This is how the skin of earthworm acts as a respiratory organ.

Question 5.
Mention the role of spiracles and trachea in the respiration of cockroaches.
Answer:
In cockroaches, 10 pairs of spiracles are present at the two lateral sides of the body. Through these pores air enters into the trachea. Trachea forms an intricate network inside the body of cockroach, which ramifies into several branches that help in gaseous exchange.

Question 6.
When and how toads and frogs perform organ-level respiration by skin?
Answer:
Frogs and toads perform organ-level respiration by skin during hibernation. They have moist, naked glandular skin. This is well permeable to gases. The cutaneous capillaries below the skin can absorb oxygen from atmosphere by diffusion, which may fulfill their need of oxygen during hibernation.

Question 7.
How does smoking affect lungs?
Answer:
Smoke of cigarettes and bidis contains different harmful compounds. This smoke enters the human lungs and forms a sticky tar which accumulates in the walls of the alveoli. Due to continuous smoking gradually the lungs lose the ability of gaseous exchange. The harmful compounds cause several diseases like emphysema, COPD and even lung cancer.

Question 8.
How many types intercostal muscles are there? Name them.
Answer:
There are two types of intercostal musclesexternal intercostal muscles and internal intercostal muscles. These muscles are present in between 12 pairs of rib bones.

Question 9.
Distinguish between trachea of cockroach and trachea of human.
Answer:

Features	Trachea of cockroach	Trachea of human
1. Number and shape	Many, which form a network	Single and straight
2. Larynx	Absent	Present
3. Opening	Opens through many paired spiracles	Opens through glottis
4. Termination	Terminates as fine blind tubules within tissues	Terminates into numerous tiny balloon-shaped alveoli

Long Questions and Answers : (5 marks for each question)

Question 1.
What is inhalation and exhalation? Briefly describe the salient features of the respiratory organs of animals. 2 + 3
Answer:
Inhalation
The mechanical process, by which organisms take in air from the environment, is called inhalation.

Exhalation
The mechanical process, by which living organisms give out carbon dioxide-rich air from their respiratory organs, into the environment, is called exhalation.

Salient features of the respiratory organs of animals
Respiratory organs of animals have three main distinctive features, which are mentioned below.
1. Moistness: A typical respiratory organ should be moist, which helps it to trap oxygen before diffusion. Moist cell membrane of unicellular organisms and moist skin of earthworms, leeches, frogs and toads trap atmospheric oxygen very efficiently.

2. Surface area: A respiratory organ should have a large surface area because more surface area improves its efficiency by transporting or exchanging enough oxygen. The thin and numerous lamellae of gills and densely packed alveoli of lungs make these two organs best suited for aquatic & aerial respiration respectively.

3. Vascularity: A respiratory organ should be well vascularised. This helps in better exchange of the respiratory gases. Rich distribution of blood capillaries in gills and lungs make these respiratory organs highly efficient for gaseous exchange.

Question 2.
Explain the role of different parts of plant body in gaseous exchange.
Answer:
Role of different parts of plant body in gaseous exchange
Plants do not have typical respiratory organs like animals. Few sites on a plant body help in exchange of O₂ and CO₂. These are stomata, lenticels, pneumatophores etc. Their role in gaseous exchange is mentioned below.

1. Stomata: Stomata are the tiny pores, present on the surface of leaves, tender stems and other parts of the plant body that help in the exchange of gases. These are the special intracellular spaces bordered by two specialised bean-shaped parenchyma cells, called guard cells, which open and close. Thus, allowing exchange of gases.

2. Lenticels: Lenticels are lens-shaped spaces, formed in the cracks on the bark of trees. These function as pores, providing the pathway for direct exchange of gases between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gases.

3. Pneumatophores: Halophytes (mainly mangrove trees) grow on saline muddy soil in the delta region of rivers. This soil has poor oxygen content. To counter it, some roots of these plants grow vertically upward against gravity and come above the soil. These roots are highly porous. These are called pneumatophores or breathing roots, which help in the exchange of gases directly from the air.

Question 3.
How do insects perform organ-level respiration with the help of trachea?
Answer:
Tracheal respiration in insects
In insects (such as cockroach), a network of a very thin-walled tubes are spread in the body. These tubes are known as trachea. Air enters into the tracheal system through tiny paired pores present on pleurites along the two sides of the body. These pores are called spiracles.

Trachea ramifies or form branches inside the body cavity, longitudinally and transversely to form a tracheal network. The finest ends of tracheal branches are called tracheoles. Each tracheole ends in a large tracheal end cell, which gives off some fine cytoplasmic processes. These processes enter into intercellular tissue fluid. Gaseous exchange occurs between the tracheal end cells and tissue fluid and finally from tissue fluid to the cells by the process of diffusion.

Question 4.
Briefly describe the main respiratory organ of fishes. How do fishes perform aquatic respiration? 3 + 2
Answer:
Structure of respiratory organ of fishes
Gills perform the respiratory function in fishes. In case of cartilaginous fishes, these are present in gill clefts and in bony fishes, these are held in gill chambers at two sides of the head, covered with a bony plate, called the operculum. A gill has a curved bony skeletal structure, called gill arch. Two rows of thin and flat gill filaments are densely arranged in a parallel manner along the gill arch like teeth of a comb. Numerous, very thin membranous folds emerge from either side of a gill filament, called gill lamellae. Gill filaments and lamellae are supplied with dense network of blood capillaries.

Mechanism of aquatic respiration in fishes
Fishes continuously open and close their mouth. When they open their mouth, fresh water flows into the buccal cavity. They open the opercula to allow water to pass through gills to flood the gill filaments before leaving the two gill chambers. As the water passes through the gills, O₂ diffuses into the blood capillaries and CO₂ diffuses out in the water. This is how, fishes perform aquatic respiration.

Question 5.
Describe the structure of human lung.
Answer:
Structure of human lung

Lungs are paired, sac-like structures located in the thoracic cavity of human body, well protected by the rib cage. Lungs remain separated from the abdominal cavity by a muscular sheet or membrane, called the diaphragm. Each lung is covered with a double layered covering called pleura. The outer layer is called parietal and the inner one is called visceral pleura. A fluid-filled space is present in between these two layers. The left lung is slightly smaller with two lobes to accommodate the heart and the right one is larger with three lobes.

A long, thin walled, tubular wind-pipe or trachea goes down vertically along the medial chest line and divides into two bronchi (singular-bronchus) before entering the lungs. Each bronchus then ramifies several times, from finer to finest air tubules, called bronchioles. Finally, each of the bronchioles ends into a tiny balloon shaped alveolus (plural-alveoli). Thus, countless alveoli form a lung. Two human lungs are composed of 30 to 50 crore of alveoli. Wall of each alveolus is rich in blood capillaries. That is why healthy lungs appear reddish pink.

Question 6.
Describe the breathing mechanism of man.
Answer:
Mechanism of human breathing
The organ-level respiration or breathing in man involves two phases-
1. Inspiration
2. Expiration. The mechanism of breathing is discussed below.

1. Inspiration: The events which occur during inspiration are as follows-

As we breathe in, diaphragm muscles contract and move down towards the abdominal cavity.
Intercostal (present in between ribs) muscles contract to pull the ribs upward to some extent.
By these two actions, the space inside the ribcage increases. This reduces the pressure inside the chest cavity and in the pleural fluid.

In this situation, thoracic pressure reaches below the atmospheric pressure. As a result, oxygen-rich air from the atmosphere rushes into the body through nostrils, nasal passage, glottis, larynx, trachea, bronchus and bronchioles to reach the alveoli. Gaseous exchange occurs in between alveolar air and capillary blood. After this exchange, the air inside lungs become rich in carbon-dioxide (CO₂). After this, the brain sends signal for expiration.

2. Expiration: The events which occur during expiration are as follows-

• The diaphragm expands and moves towards the chest cavity.
• Intercostal muscles relax and the ribs go downward to their normal position.
• Due to the above two actions, the internal volume of the chest cavity reduces. As a result, pressure increases in the pleural fluid, as well as in the lungs.
• The lungs contract and the CO₂-rich air, inside the lung, is pushed out along the reverse path.

Question 7.
How do the lungs get weak and diseased? How can the lungs be kept fit? 3 + 2
Answer:
Reason of weak and diseased lungs
Lungs are very important organs in our body, which are involved in respiration. If lungs do not perform their function perfectly, we will fall sick. Lungs lose its efficienc due to aging, obesity, infections and in most cases due to smoking. A dark coloured tar is deposited in the lungs of smokers, that contains several potential carcinogens (cancer inducing substances), leading to lung cancer.

Smokers develop a chronic lung disease, called emphysema. In this case, gaseous exchange reduces and the efficiency of lungs decline permanently. Passive smokers (who unconsciously inhale the smoke released by active smokers) are the worst victims of this bad habit and also suffer from the same diseases. Due to allergic effect, a person may suffer from asthma and COPD (Chronic Obstructive Pulmonary Disease). Infection with Mycobacterium tuberculosis may lead to a serious lung disease, called tuberculosis, whose symptoms are coughing (sometimes with sputum with blood), chest pain, weakness, weight loss, fever etc.

Methods of keeping the lungs fit
Breathing exercise or ‘pranayam’ keeps our lungs healthy. The basis of this exercise is steady, forceful & rhythmic inspiration & expiration. It increases the extensibility of the lungs and thus, increases the oxygen intake capacity of the body. But, pranayam should be practiced under the proper guidance of a competent yoga teacher. Moreover, swimming, cycling, jogging and even walking keeps our lungs healthy.

Detailed explanations in West Bengal Board Class 9 Life Science Book Solutions Chapter 3.1D Movement of Water, Minerals, Food and Gases offer valuable context and analysis.

WBBSE Class 9 Science Chapter 3.1D Question Answer – Movement of Water, Minerals, Food and Gases

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

Question 1.
By which process water molecules enter through the cell membrane of root hair cells?
Answer:
Water molecules enter through the cell membrane of root hair cells by endosmosis.

Question 2.
How do cells of aquatic plants absorb dissolved CO₂ from water?
Answer:
Aquatic plants absorb dissolved CO₂ from the water by diffusion.

Question 3.
How is facilitated diffusion different from active transport?
Answer:
In active transport, chemical energy is needed in the form of ATP but facilitated diffusion does not need energy.

Question 4.
In which type of active transport, two different diffusible molecules or ions move against each other at the same time?
Answer:
In antiport, two different diffusible molecules or ions move against each other at the same time.

Question 5.
In which type of active transport, a single type of ion or molecule moves through the cell membrane?
Answer:
In uniport, a single type of ion or molecule moves through the cell membrane.

Question 6.
In which type of active transport, two different ions or molecules move together in the same direction through a cell membrane?
Answer:
In symport, two different ions or molecules move together in the same direction through a cell membrane.

Question 7.
Name two biomolecules, which pass through the cell membrane by active transport.
Answer:
Glucose and amino acids pass through the cell membrane by active transport.

Question 8.
Mention two matters, which are taken into a cell by passive transport.
Answer:
Oxygen and water are two matters, which are taken into a cell by passive transport.

Question 9.
Diffusion pressure deficit increases in leaves during daytime due to which phenomenon?
Answer:
Diffusion pressure deficit increases in leaves during the daytime due to transpiration.

Question 10.
How does sap pass through the cells of cortex of root?
Answer:
Sap passes through the cells of cortex of root by cell to cell osmosis.

Question 11.
Which pressure is created within the xylem vessels by the inflow of sap from the root?
Answer:
Root pressure is created within the xylem vessels by the inflow of sap from the root.

Question 12.
Which force pulls the sap up from roots to the leaves of tall plants?
Answer:
Transpiration pull helps the sap to reach the top leaves of tall plants.

Question 13.
How much pulling force may transpiration pull create in a xylem vessel?
Answer:
About 20 atmospheric pressure is created in the xylem vessels of taller plants by transpiration pull.

Question 14.
How does the size of diffusible molecules affect the rate of diffusion?
Answer:
Larger size of diffusible molecules reduces the rate of diffusion and vice versa.

Question 15.
How does the density of diffusible molecules affect the rate of diffusion?
Answer:
Higher density of diffusible molecules increases the rate of diffusion.

Question 16.
Due to which pressure young meristematic cells grow in size?
Answer:
Young meristematic cells grow in size due to turgor pressure.

Question 17.
Name the scientist who proposed the ‘Root Pressure Theory’.
Answer:
British scientist Stephen Hales proposed the ‘Root Pressure Theory’.

Question 18.
Who proposed the ‘Transpiration pull and Cohesion Tension Theory’ to explain the ascent of sap?
Answer:
Scientists Dixon and Joly proposed the ‘Transpiration pull and Cohesion tension theory’ to explain the ascent of sap.

Question 19.
Give an example of an impermeable membrane.
Answer:
An example of an impermeable membrane is plastic sheet.

Question 20.
Give an example of a permeable membrane.
Answer:
Cell wall is an example of a permeable membrane.

Question 21.
Give an example of a semi-permeable membrane.
Answer:
An example of a semi-permeable membrane is parchment paper.

Question 22.
By which type of active transport, two different diffusible molecules are carried by a single carrier protein?
Answer:
In coupled transport, two different diffusible molecules are carried by a single carrier protein.

Question 23.
Name the components of xylem, which play a major role in the transport of water.
Answer:
The components of xylem, which play a major role in the transport of water are tracheid and trachea.

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

Question 1.
What is meant by transport?
Answer:
The process by which food materials, mineral salts, hormones and various gases reach the cells of living organisms and different harmful metabolic waste matters are sent from tissues to respective excretory organs through liquid medium, is called transport.

Question 2.
How is facilitated diffusion different from simple diffusion
Answer:
In facilitated diffusion, a carrier molecule or a channel protein in the membrane helps the entry of the diffusible molecules through it, but in simple diffusion, carrier protein is not required.

Question 3.
What is meant by passive transport?
Answer:
Passive transport is a process by which any molecule or ion of a substance passes through cell membrane along concentration gradient without consuming any metabolic energy. ExampleDiffusion and osmosis.

Question 4.
What is meant by active transport?
Answer:
Active transport is a process by which any molecule or ion needs some metabolic energy to pass through a cell membrane by the help of carrier protein, against concentration gradient. Example-Intake of glucose molecules by a cell.

Question 5.
What is diffusion?
Answer:
The physical process by which molecules or ions of any substance, moves from a region of higher concentration to a region of lower concentration, with the help of their own kinetic energy, is called diffusion. Example-Aroma of incense stick spreads to all corners of the room by diffusion.

Question 6.
What is meant by osmosis?
Answer:
If two solutions of different concentration, prepared from the same liquid solvent, are separated by a semi-permeable membrane, the solvent molecules move from the region of higher solvent concentration towards the region of lower solvent concentration, until equilibrium is attained. This physical phenomenon is known as osmosis. Example-Raisins swell in water due to osmosis.

Question 7.
What is meant by facilitated diffusion?
Answer:
Facilitated diffusion is a type of diffusion, where diffusible molecules pass through a cell membrane with the help of some channel proteins present in it. In this process, no metabolic energy is needed.

Question 8
What is meant by root pressure? Mention the importance of root pressure.
Answer:

• Root pressure: The cumulative turgor pressure created in the cells, surrounding the xylem vessels of the root, due to absorption of sap is known as root pressure.
• Importance: Root pressure pushes the sap into the xylem vessels through their thick cell wall and drives the sap upward.

Question 9.
What is cohesive force? What is meant by adhesive force.
Answer:

• Cohesive force: The force of attraction between two particles or molecules of a same substance, is called cohesion force. Inside the xylem vessels water droplets remain attached to each other by cohesive force.
• Adhesive force: The force of attraction between the particles of different substances, is called the adhesive force. The water droplets remain attached to the wall of xylem vessel by adhesive force.

Question 10.
What is transpiration pull?
Answer:
In xylem vessels, uninterrupted water column is formed by cohesive-adhesive force. These columns extend from the roots to the stomata of the leaves. During transpiration, when a molecule of water leaves the stomatal opening, it applies an upward pulling force on the receding water column, which is known as transpiration pull.

Question 11.
What is meant by ascent of sap?
Answer:
The transport of water and minerals, known as sap, from root to the leaves through xylem vessels against the force of gravity, is known as the ascent of sap.

Question 12.
The fragrance of a perfume, sprayed at one corner of a room, can be felt in the entire room after some time. Which phenomenon is responsible for this?
Answer:
The fragrance of a perfume, sprayed at one corner of a room, can be felt in the entire room after some time due to a phenomenon called diffusion.

Question 13.
Name the forces which control the ascent of sap in plants.
Answer:
The forces which control the ascent of sap in plants are-

• root pressure
• transpiration pull
• adhesive force and
• cohesive force.

Question 14.
Give two examples of liquid-liquid diffusion.
Answer:
Two examples of liquid-liquid diffusion are-

• Diffusion between water and ink and
• Diffusion between water and sugar syrup.

Question 15.
Give two examples of liquid-solid diffusion.
Answer:
Two examples of liquid-solid diffusion are-

• Diffusion between water and sugar crystal and
• Diffusion between water and copper sulphate (CuSO₄)crystals.

Question 16.
Give two examples of solid-gas diffusion.
Answer:
Two examples of solid-gas diffusion are-

• Diffusion between asafoetida and air and
• Diffusion between camphor and air.

Question 17.
Give two examples of gas-gas diffusion.
Answer:
Two examples of gas-gas diffusion are-

• Diffusion between air and ammonia gas and
• Diffusion between air and smoke of inscence stick.

Question 18.
Mention two examples of carrier proteins which help in active transport.
Answer:
Two examples of carrier proteins which help in active transport are-

• Sodium-Potassium pump (Na⁺/K⁺-ATPase pump) and
• Proton pump (H- ATPase pump).

Question 19.
Define hypertonic solution.
Answer:
A solution that has a higher concentration of solutes on the outer side of a cell in comparison to the inner side of it, is known as a hypertonic solution.

Question 20.
What is an isotonic solution?
Answer:
A solution that has identical concentration of solutes on both outer and inner side of a cell, is known as isotonic solution.

Question 21.
Define a hypotonic solution.
Answer:
A solution that has lower concentration of solutes on the outer side of a cell in comparison to the inner side of it, is known as hypotonic solution.

Question 22.
What is absorption in plants?
Answer:
The physical process by which water and mineral salts enter the plant body through root hair by the process of endosmosis, is called absorption.

Question 23
Why the water potential of any solution is always negative?
Answer:
The water potential of pure water is zero. Thus, solute mixed any solution always has negative water potential.

Question 24.
What are the major components of pholem sap?
Answer:
The major components of pholem sap arecarbohydrate, amino acid, minerals and organic acid and water.

Question 25.
Mention the differences between active transport and passive transport.
Answer:

Feature	Active transport	Passive transport
1. Metabolic Energy	Cellular metabolic energy is requried	Cellular metabolic energy is not required
2. Enzymes	Play important role	Play no role
3. Transpiration pull	Plays no role	Plays major role
4. Effect of O2	Transport is hampered in the absence of free O2	Transport is not effected by the absence of free O2

Question 26.
Mention the differences between diffusion and osmosis.
Answer:

Feature	Diffusion	Osmosis
1. Semi-permeable membrane	Not necessary for diffusion	Essential for osmosis
2. Medium	Occurs between different media (solid, liquid, gas)	Occurs between two liquids
3. Transportability	Both solute and solvent are transported	Only solvents are transported

Long Questions and Answers : (5 marks for each question)

Question 1.
Mention the role of different factors in controlling diffusion.
Answer:
Role of different factors in controlling diffusion

Various factors play important role in controlling the rate of diffusion. These are mentioned below.

1. Temperature: With the increase in temperature of the medium, movement of diffusible molecules increase. Therefore, increase in temperature enhances the rate of diffusion.

2. Size of diffusible molecules: Larger size of the diffusible molecules restricts their movement. Therefore, larger molecules show slower diffusion rate.

3. Extent of concentration gradient: Rate of diffusion also depends upon the concentration gradient of molecules of both media. The greater the difference in concentration, the more rapid the diffusion. The closer the distribution of both molecules gets to equilibrium, the slower the rate of diffusion becomes.

4. Solubility: A molecule with higher rate of solubility, diffuses quickly in a given medium.

5. Viscosity of the medium: The rate of diffusion is inversely proportional to the viscosity of the medium. That is, if the viscosity of the medium is high, then the rate of diffusion will be lower and vice versa.

Question 2.
Mention the salient features of diffusion. Give two examples of diffusion in plants.
Answer:
The salient features of diffusion:

The salient features of diffusion are as follows—

• Diffusible molecules of solid, liquid or gaseous substances can diffuse within either liquid or in gaseous medium.
• Diffusible molecules move from a region of higher concentration to a region of lower concentration.
• Diffusion of molecules continues until homogeneity’ is attained, i.e. the concentration of molecules in both directions becomes same.
• It is a passive process, i.e. does not require any metabolic energy.

Example of diffusion in plants
Two examples of diffusion in plants are —

• passive absorption of ions and
• absorption of O and CO₂ in cells.

Question 3.
What is meant by plasmolysis and deplasmotysis? What happens when a living cell is placed in a solution with concentration identical to its protoplasm?
Answer:
Plasmolysis:
If a cell with intact cell membrane is placed in a hypertonic solution, i.e. a solution with concentration higher than the concentration of the protoplasm of the cell, water from the protoplasm will gradually move out from the ceil through its cell membrane by exosmosis. In this case the protoplasm of the cell will shrink and the cell will appear wrrinkied. This phenomenon is called plasmolysis.

Deplasmolysis
If a plasmolysed cell is placed in a hypotonic solution, i.e. a solution with concentration lower than the concentration of the protoplasm of the cell, water from the outer medium will enter into the protoplasm through the cell membrane by endosmosis. In this case, the protoplasm will get more water and the cell will be distended. This phenomenon is called deplasmolysis.

Fate of living cell in isotonic solution
If a living cell is placed in a solution with concentration identical to its protoplasm, i.e., isotonic solution, water from outer medium and from the protoplasm will move through the cell membrane at same rate against each other. Therefore, no change will appear in the cell.

Question 4.
Mention the salient features of osmosis. Mention three roles of osmosis in plant body.
Answer:
The salient features of osmosis:

The salient features of osmosis have been mentioned below.

• Osmosis occurs only in liquid medium.
• This process involves the presence of semi-permeable membrane.
• Solvent molecules move from a region of its higher concentration to a region of lower concentration across the semi-permeable membrane. Movement of solutes does not occur in osmosis.
• Movement of solvent molecules continues until homogeneity is attained. In osmosis, rate of movement of solvent molecules on either side of the semi-permeable membrane becomes the same.
• It is a passive process, i.e. does not require any metabolic energy.

Role of osmosis in plant body
In plants, osmosis helps in-

• absorption of water,
• opening and closing of the stomata and
• maintaining turgidity of cell.

Question 5
Briefly describe the characteristic features of active transport. Mention the importance of cell to cell transport.
Answer:
The characteristic features of active transport:

The characteristic features of active transport has been briefly described below.

• In this process, the movement of substances occur from a region of lower concentration to a region of higher concentration.
• The cell membrane has different carrier proteins that remain suspended in its lipid bi-layer. The substances to be transported, first bind to a specific carrier protein and then passes from one side of the membrane to another.
• The movement of substances against the concentration gradient requires the involvement of energy, which is supplied by ATP. In plants, active transport occurs during absorption of mineral ions by plant roots, loading of sugar into the phloem etc.
• Active transport requires a semi-permeable membrane.

Importance of cell to cell transport:

The importance of cell to cell transport are as follows

• Diffusible materials like O₂ ,CO₂ etc. move from one cell to the next, by cell to cell diffusion.
• Water passes from one cell to another, by cell to cell osmosis.
• Sugar is loaded into the phloem cells from the leaf cells by means of cell to cell active transport.

Question 6.
How does ascent of sap occur in a plant?
Answer:
Ascent of sap:

Transpiration is the process that acts as a driving force for the ascent of sap, from roots to the top of a tree, via xylem vessels. The sequence of events during ascent of sap occurs in the following order:

• Release of water through stomata by transpiration.
• Lowering of turgor pressure of leaf cells due to loss of water.
• Uptake of water by leaf cells from the xylem elements causing a vacuum in the xylem vessels.
• Generation of a vertically upward suction force on the water column in the xylem vessel, called transpiration pull.
• Cohesive and adhesive forces of water molecules maintain the uninterrupted water column within the xylem vessels.
• Roots absorb water and minerals from the soil by imbibition and endosmosis, that moves through the endodermis and increases turgor pressure in the cells surrounding the xylem vessels.
• The mounting root pressure pushes sap into xylem vessels and starts to drive it against gravity towards the leaves upwards.

Question 7.
How is food transported in different parts of the plant body?
Answer:
Transportation of food in plant body:

Transportation of food in plants occurs through sieve tubes of phloem. The cells of selve tube are arranged one after the other forming a continuous structure. Regarding the mechanism of this process, ‘pressure flow hypothesis’ by Ernst Munch, is the most accepted one. According to this hypothesis, following events occur during food transport in plants.

1. Transfer of food from mesophyll tissue to sieve tube: In mesophyll tissues, glucose produced by photosynthesis is soon converted into a larger sugar (sucrose). The sucrose solution is then transferred to the sieve tube via bundle sheath cells, phloem parenchyma and companion cells by cell to cell transport.

2. Creation of pressure within sieve tube: With the entry of sucrose, the cytoplasm of sieve tube becomes denser. As a result, a concentration gradient develops between the sieve tube & neighbouring xylem vessels. Due to this, water moves into the sieve tube from xylem vessels by osmosis, thereby, creating additional pressure within the sieve tubes.

3. Flow of food: This mounting pressure produced within the sieve tube, pushes the food solution to different parts of the plant body. Finally, the sucrose solution enters into the tissue cells from the sieve tube.

Detailed explanations in West Bengal Board Class 9 Life Science Book Solutions Chapter 3.2B Cellular Level Respiration offer valuable context and analysis.

WBBSE Class 9 Science Chapter 3.2B Question Answer – Cellular Level Respiration

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

Question 1.
Which type of respiratory process generates energy inside the living cell?
Answer:
Internal or cellular respiration generates energy inside the living cell.

Question 2.
What is meant by respiratory substrate?
Answer:
The compounds, which are oxidised during cellular respiration to release energy, are known as respiratory substrates.

Question 3.
In which form does respiratory substrate liberate energy during cellular respiration?
Answer:
During cellular respiration, energy is liberated from respiratory substrate in the form of ATP.

Question 4.
Where do reactions of glycolysis take place during cellular respiration?
Answer:
Reactions of glycolysis take place in the cytoplasm during cellular respiration.

Question 5.
What is meant by glycolysis?
Answer:
The breakdown of glucose by enzymes, releasing energy and pyruvic acid, is called glycolysis.

Question 6.
How many pyruvic acid molecules are formed at the end of glycolysis?
Answer:
Two pyruvic acid molecules are formed at the end of glycolysis.

Question 7.
Where do the reactions of Krebs cycle take place?
Answer:
Reactions of Krebs cycle occur in the mitochondria.

Question 8.
Mention the by-products of Krebs cycle.
Answer:
The by-products of Krebs cycle are CO₂, reduced NAD and FAD (i.e. NADH + H⁺ and FADH₂ respectively).

Question 9.
Which reactions of respiration occur in the inner membrane of mitochondria?
Answer:
The reactions of electron transport system or terminal respiration occur in the inner membrane of mitochondria.

Question 10.
In which phase of aerobic respiration is ATP produced?
Answer:
ATP is produced by ETS (electron transport system) of aerobic respiration.

Question 11.
Mention two organic end-products of anaerobic respiration.
Answer:
Lactic acid and ethyl alcohol are two organic end-products of anaerobic respiration.

Question 12.
Name a type of animal tissue, where anaerobic respiration takes place.
Answer:
Anaerobic respiration occurs in the voluntary muscles of animals.

Question 13.
Which organic compound is formed in muscle cells due to anaerobic respiration?
Answer:
Lactic acid is formed in muscle cells due to anaerobic respiration.

Question 14.
Which organic compound is produced in plant cells due to anaerobic respiration?
Answer:
Ethyl alcohol is produced in plant cells by anaerobic respiration.

Question 15.
Which organic compound is produced by fermentation of milk?
Answer:
Lactic acid is produced by fermentation of milk.

Question 16.
Which organic compound is produced by fermentation of glucose or sucrose in oxygen free condition?
Answer:
Ethyl alcohol is produced by fermentation of glucose or sucrose in oxygen free condition.

Question 17.
Name an enzyme present in yeast, wihch helps in aicoholic fermentation of sugar solution.
Answer:
Enzyme zymase is present in yeast, which helps in alcoholic fermentation of sugar solution.

Question 18.
Which enzyme, present in Lactobacillus, helps in fermentation of milk-sugar?
Answer:
Lactate dehydrogenase is the enzyme, present in Lactobacillus, which helps in fermentation of milk-sugar.

Question 19.
Where does aerobic respiration take place?
Answer:
Aerobic respiration takes place in all organisms living in air, water and soil in contact with free molecular oxygen.

Question 20.
How many high energy bonds are present in ATP?
Answer:
Two high energy bonds are present in ATP.

Question 21.
How much energy is released during hydrolysis of 1 molecule of ATP?
Answer:
During hydrolysis of 1 molecule of ATP, 7.3 kcal energy is released.

Question 22.
Which cell organelies are called ‘energy transducers’?
Answer:
Those cell organelles which convert one form of energy into another, are called ‘energy transducers’.

Question 23.
Name two organelles which act as energy transducers.
Answer:
Two organelles which act as energy transducers are chloroplast and mitochondrion.

Question 24.
Name the scientist who first observed the difference between respiration and combustion.
Answer:
Antoine Lavoisier first observed the difference between respiration and combustion.

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

Question 1.
What is respiration?
Answer:
Respiration is a catabolic process, which involves the intake of oxygen within cells and liberation of kinetic energy by oxidation of food or respiratory substrates, for performing different life activities.

Question 2.
What is meant by cellular respiration?
Answer:
The bio-chemical process by which food or respiratory substrates are oxidised within the cells to liberate kinetic energy in the form of ATP, is known as cellular respiration.

Question 3.
What is meant by aerobic respiration?
Answer:
Aerobic respiration is a type of cellular respiration, where respiratory substrate is oxidised completely in the presence of free oxygen to discharge carbon dioxide and water as by-products and to liberate the total energy from the substrate.

Question 4.
Write down the chemical equation of aerobic respiration.
Answer:
The chemical equation of aerobic respiration is mentioned below.

Question 5.
What is meant by anaerobic respiration?
Answer:
Anaerobic respiration is a type of cellular respiration, where respiratory substrate is incompletely oxidised in absence of free molecular oxygen but by the help of the oxygen of inorganic compounds like \(\mathrm{NO}_3^{-}\) \(\mathrm{SO}_4^{2-}\), \(\mathrm{CO}_3^{2-}\), etc. to release carbon dioxide as by-products and to a little amount of energy from the substrate, along with organic compounds.

Question 6.
In which organisms anaerobic respiration occurs?
Answer:
Anaerobic respiration occurs in some bacteria such as Paracoccus denitrificans, Methanobacterium autotrophicum, Bacillus licheniformis etc., few fungi such as yeast, protozoa, all endoparasitic worms (Taenia, Ascaris, Echinococcus etc.). It also occurs in the seeds and few other cells of plants and voluntary muscle cells of animals.

Question 7.
What is meant by fermentation?
Answer:
Fermentation is a typical anaerobic, enzymedependent process of incomplete oxidation of sugar, which produces different organic compounds (ethyl alcohol, lactic acid, butyric acid etc.) with partial liberation of energy from the respiratory substrate.

Question 8.
Write down the chemical equation of ethyi alcohol fermentation.
Answer:
The chemical equation of ethyl alcohol fermentation is mentioned below.

Question 9.
Write down the chemical equation of lactic acid fermentation.
Answer:
The chemical equation of lactic acid fermentation is as follows-

Question 10.
What is meant by alcoholic fermentation?
Answer:
Alcoholic fermentation is a special type of fermentation, where yeast (Saccharomyces) ferments sugar (glucose, fructose, sucrose etc.) solutions to produce ethyl alcohol with the help of a typical enzyme, zymase. In this process, CO₂ and a little energy are also released.

Question 11.
What is meant by lactic acid fermentation?
Answer:
The fermentation process, where certain bacteria (Lactobacillus) ferment milk-sugar (lactose), to produce lactic acid in absence of O₂, liberating a little amount of energy ( 36 kcal ), called lactic acid fermentation.

Question 12.
What is glycolysis?
Answer:
Glycolysis is an oxygen-independent reaction, where glucose, within the cytoplasm of living cells, is broken into pyruvic acid molecules through a series of enzyme-mediated reactions and in this process produce NADH+H⁺, H₂ O and ATP as by-products.

Question 13.
Why is glycolysis called EMP path?
Answer:
Scientists Embden, Meyerhof and Parnas discovered the reaction pathway of glycolysis. Therefore, after the first letter of the names of these three scientists, glycolysis is known as EMP path.

Question 14.
What is Krebs cycle?
Answer:
Krebs cycle is a cyclic reaction pathway, through which, acetyl Co-A, the decarboxylated end product of pyruvate (produced in glycolysis), is oxidised in steps to produce CO₂ and H₂ O and in this process, NAD and FAD are reduced to NADH+H⁺and FADH₂ respectively. It is named after scientist Hans Krebs.

Question 15.
Why is Krebs cycle known as TCA cycle and citric acid cycle?
Answer:
Citric acid is produced in the first step of Krebs cycle, therefore it is called Citric acid cycle. Citric acid contains three carboxylic groups, therefore, this cycle is also known as tricarboxylic acid cycle or TCA cycle.

Question 16.
What is meant by terminal respiration?
Answer:
Terminal respiration is the last step of aerobic respiration, where NADH+H⁺and FADH₂, produced in giycolysis and Krebs cycle, are oxidised by electron carriers, situated in the inner membrane of mitochondria, and hydrogen is oxidised by the atmospheric oxygen to form water and piroduce ATP.

Question 17.
Mention the four phases involved in aerobic respiration.
Answer:
The four phases involved in aerobic respiration are-

• glycolysis
• oxidation of pyruvate
• kerbs cycle
• terminal respiration.

Question 18.
What is ATP synthases?
Answer:
ATP synthase is a enzyme, present on the inner membrane of mitochondria and helps in the synthesis of ATP.

Question 19.
How does organ-level respiration differs from cellular respiration?
Answer:

Features	Organ level respination	Cellatar respiration
1. Nature of reaction	It is a physical process	It is bio-chemical process
2. Site of respiration	Different respiratory organs are involved	All living cells are involved
3. Occurence of chemical reaction	No chemical reaction occurs	Various chemical reactions occur
4. Steps involved	Inspiration, gaseous exchange and expiration	Glycolysis, Krebs cycle and terminal respiration

Question 20.
Distinguish between glycolysis and Krebs cycle.
Answer:

Features	Glycolysis	Krebs cycle
1. Occurrence	Cytoplasm	Mitochondria
2. Entry-level substrate	Glucose	Acetyl Co-A
3. Reaction path	Straight	Circular
4. End product	Pyruvate, ATP, NADH + H+	CO2, NADH + H+, FADH2 and GTP

Question 21.
Distinguish between combustion and respiration.
Answer:

Features	Combustion	Respiration
1. Nature of reaction	Physico-chemical process	Bio-chemical process
2. Enzymes	No role	Plays essential role
3. Free oxygen	Essential	May occur in absence of oxygen
4. Regulation of oxidation	Very fast and not controlled	Slow and controlled
5. Energy generated	Heat and light energy	Only heat energy

Question 22.
Distinguish between alcoholic fermentation and lactic acid fermentation.
Answer:

Features	Alcoholic fermentation	Lactic acid fermentation
1. Occurence	Occurs in yeast cell	Occurs in voluntary muscles and certain bacterial cells
2. CO2 production	Occurs	Does not occur
3. End-products	Ethyl alcohol	Lactic acid

Long Questions and Answers : (5 marks for each question)

Question 1.
Briefly describe the process of glycolysis with the help of a schematic diagram.
Answer:
Glycolysis
Glycolysis is the primary step of cellular respiration occurring in cytoplasm of all living cells. By this process, glucose is enzymatically broken into two pyruvic acids (3C) through a straight chain reaction path. Each step requires a specific enzyme which acts as biocatalyst.
In this metabolic process, glucose is first converted into glucose 6-phosphate and then to fructose 1, 6-bisphosphate. In this phase, two ATP molecules are consumed. In the next step, this fructose

1, 6-bisphosphate is broken into two 3C compounds-glycerabldehyde 3-phosphate and dihydroxyacetone phosphate. Enzymatically, this dihydroxyacetone phosphate is transformed into glyceraldehyde 3 phosphate. At the final phase, two molecules of glyceraldehyde 3phosphate transforms step-by-step to form two molecules of pyruvic acid. By glycolytic breakdown of one molecule of glucose, four ATP molecules are produced and two are consumed, therefore, two ATP molecules are net gained. In this reaction, two molecules of NADH + H⁺ are also produced.

Question 2.
Briefly describe the reaction process of Krebs cycle with the help of schematic diagram.
Answer:
Krebs cycle

Krebs cycle is the second major phase of aerobic respiration. This reaction occurs in the mitochondria in a cyclic reaction path, where a 6 carbon substrate, citric acid is converted step-by-step into 5 C and 4 C substrates. The entry-level substrate of Krebs cycle is acetyl Co-A, which is produced from pyruvic acid, the end product of glycolysis. In Krebs cycle, acetyl Co-A and oxaloacetic acid combine to form citric acid. This is the initial product of this cycle.

In this process CO₂, is released in steps. The other products are NADH+H⁺, FADH₂ and GTP. This GTP is transformed into ATP directly. The other two products NADH+H⁺ and FADH₂ are oxidised by dissociation of hydrogen through electron transport system.

Question 3.
Mame the enzyme present in the oxysomes of mitochondria. How does terminal respiration occur in a cell of any aerobic organism? 1 + 4
Answer:
Enzyme in oxysome
ATP synthetase enzyme is present in the oxysomes of mitochondria.

Terminal respiration
Terminal respiration is the final phase of aerobic reaction, which involves the production of ATP and H₂ O. This is the energy generating, i.e., ATP producing final phase of cellular respiration. NADH + H⁺ and FADH₂, (reduced hydrogen carriers) which are produced during glycolysis, decarboxylation of pyruvic acid & Krebs cycle, are oxidised in this reaction path. At first, hydrogen atoms are released from NADH + H⁺ and FADH₂. Then each hydrogen atom releases one electron, which is then transported by iron containing electron carriers cytochrome. This process generates huge chemical energy, which finally produces energy-rich ATP molecules. So, this reaction pathway is also known as electron transport system or ETS. The hydrogen atoms, released from NADH+ H⁺ and FADH₂ finally react with O₂ present in the atmosphere to produce H₂ O.

Question 4.
Mention the significance of respiration.
Answer:
Significance of respiration
The significance of respiration are mentioned below.
1. Conversion of energy and ATP production: The potential energy stored in food, is converted into kinetic energy by respiration. This energy is dissipated as heat and some portion of it is stored in ATP within the cells, as chemical energy for future use.

2. Maintenance of O₂-CO₂ balance: During respiration, atmospheric oxygen is consumed and carbon dioxide is released. Whereas, photosynthesis does the opposite. Thus, photosynthesis and respiration jointly maintain the balance of oxygen and carbon dioxide in the environment.

3. Economic importance: Fermentation of flour (starch) by yeast makes cakes and breads puffy. Ethyl alcohol is a fermentation product, which has great economic importance for medicinal purpose and to prepare alcoholic beverages. Cheese, butter, curds are prepared by fermentation of milk. Some vitamins like vit B₁, vit B₁₂, vit C etc. are also produced in the body by bacterial fermentation.

4. Excretion: Various excretory products like ammonia, ketone body, alcohol, water vapour, volatile fatty acids, etc., are given out of the body through respiration.

5. Maintenance of Acid-Base balance: Since CO₂ is liberated during respiration, it helps to maintain acid-base balance in the body.

6. Regulation of temperature: When animals exhale, certain amount of heat is liberated from their bodies, thus regulating the temperature of the body.

7. Light generation: Certain deep-sea animals, like Ctenophorans and insects, like fireflies can generate light. This phenomenon is called bioluminescence. This light is generated from the chemical energy, gained by respiration.

8. Electrical power generation: Some fishes like Torpedo and electric eel can generate huge electrical power within their electric organs to kill preys. Respiration produces this power from chemical energy.

Question 5.
Compare among aerobic respiration, anaerobic respiration and fermentation.
Answer:
Comparison among aerobic respiration, anaerobic respiration and fermentation

Question 6.
Distinguish between photosynthesis and respiration.
Answer:
Differences between photosynthesis and respiration

Detailed explanations in West Bengal Board Class 9 Life Science Book Solutions Chapter 3.1C Transpiration offer valuable context and analysis.

WBBSE Class 9 Science Chapter 3.1C Question Answer – Transpiration

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

Question 1.
Which tiny pores, present on the leaf surface help in gaseous exchange and liberation of excess water as vapour?
Answer:
Stomata are the tiny pores, present on the leaf surface, helping in gaseous exchange and liberation of excess water as vapour.

Question 2.
Which cells control the opening and closing of stomata?
Answer:
Guard cells control the opening and closing of stomata.

Question 3.
Name the small lens-shaped pores present on the stems of plants, which serve as site of transpiration.
Answer:
The small lens-shaped pores present on the stems of plants, which serve as site of transpiration, are called lenticels.

Question 4.
Which layer on the leaf surface prevents transpiration in desert plants?
Answer:
Cuticle layer on the leaf surface prevents transpiration in desert plants.

Question 5.
At which time of a day does transpiration occurs at the maximum rate?
Answer:
During mid-day, transpiration occurs at the maximum rate.

Question 6.
Why does transpiration occur mainly during the daytime?
Answer:
Light helps in opening of the stomata, therefore, transpiration occurs mainly during the daytime.

Question 7.
In which type of plants do stomata open at night?
Answer:
In some desert plants stomata open at night.

Question 8.
Why do stomata of some desert plants open at night?
Answer:
To prevent excess water loss during daytime, stomata of some desert plants open at night.

Question 9.
In lotus, on which surface of the leaf are stomata present?
Answer:
In lotus, stomata are present on the dorsal surface of the leaf.

Question 10.
In which season of the year does transpiration in terrestrial plants reaches the peak?
Answer:
In dry summer season, transpiration in terrestrial plants reaches the peak.

Question 11.
Why are the leaves of many desert plants modified into spines?
Answer:
The leaves of many desert plants are modified into spines in order to prevent water loss by transpiration.

Question 12.
Why do many desert plants possess dense hairs on the body surface?
Answer:
Dense hairs prevent direct air contact on leaf surface and thus, reduce the rate of transpiration, therefore, many desert plants possess dense hairs on the body surface.

Question 13.
How does air flow affect the rate of transpiration?
Answer:
Rate of transpiration increases with the increase in air flow.

Question 14.
Why is the rate of transpiration low in pine leaves?
Answer:
Needle-shaped pine leaves possess lesser number of stomata, which are slightly sunken in nature, so rate of transpiration is low in pine leaves.

Question 15.
Which instrument is used to measure the rate of transpiration?
Answer:
Ganong’s potometer is used to measure the rate of transpiration.

Question 16.
Why is rate of transpiration higher on the ventral surface of the leaves of dicotyledonous plants?
Answer:
Leaves of dicotyledonous plants possess more stomata on the ventral surface, therefore, the rate of transpiration is higher on that side.

Question 17.
Mention the phenomenon through which plants give out excess water in the form of droplets?
Answer:
The phenomenon through which plants give out excess water in the form of droplets, is known as guttation.

Question 18.
In which side of an isobilateral leaf, do we find more number of stomata?
Answer:
In an isobilateral leaf, stomata are distributed equally on both sides of the leaf.

Question 19.
How is the rate of transpiration affected on a rainy day?
Answer:
Since the percentage of water vapour is high in the atmosphere on a rainy day, the rate of transpiration decreases.

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

Question 1.
How do guard cells control the opening and closing of stomata?
Answer:
In the presence of light, hygroscopic pressure increases inside the guard cells. Due to unequal elasticity of cell walls of the two opposite sides of each guard cell, the cells bend like beans. As a result, the space between two guard cells widens to open the stomata. In the absence of light, hygroscopic pressure decreases inside the guard cells and the stomata close.

Question 2.
Why is the stomata of lotus plant present on the dersal surface of the leaves?
Answer:
The lotus leaves float on the water surface and the stomata are present on the dorsal surface to keep direct contact with air. This typical placement of stomata helps lotus leaves to maintain gaseous exchange with atmosphere and thus, perform transpiration.

Therefore, a plant with wider leaves shows higher rate of transpiration than a plant with narrow leaves. Also, in some plants (e.g. cactus) leaves are modified into spines to reduce transpiration. Thus, shape of leaves influence the rate of transpiration.

Question 3.
Why do plants with wider leaves wilt in summer but a pine tree remains unaffected?
Answer:
Plants with wider leaves have more number of stomata, through which they lose excess water in form of vapours due to transpiration on summer days. This loss of water makes the cells turgid and the protoplasm shrinks. This results into wilting of these plants. Whereas, a pine tree possesses needle-like leaves with very little number of sunken stomata. Therefore, pine trees lose much less water by transpiration and remain unaffected even on a summer day.

Question 4.
Why is transpiration called a necessary evil?
Answer:
Transpiration helps plants in the ascent of sap, removal of excess water, cooling the plant body, maintaining the water balance. On the other hand, excessive transpiration causes decrease in protoplasmic water content and thus, resulting into shrinkage of cells followed by wilting of leaves and tender branches. This is why, transpiration is called a necessary evil.

Question 5.
How does shape of leaves influence the rate of transpiration?
Answer:
Number of stomata is directly proportional to the rate of transpiration. A wider leaf has more stomata than a leaf with narrow leaf lamina. Therefore, a plant with wider leaves shows higher rate of transpiration than a plant with narrow leaves. Also, in some plants (e.g. cactus) leaves are modified into spines to reduce transpiration. Thus, shape of leaves influence the rate of transpiration.

Question 6.
If all the leaves of a plant are applied with a layer of vaseline, what will happen to it?
Answer:
If all the leaves of a plant are applied with a layer of vaseline, the stomatal openings will be sealed completely. In this situation, the plants will not be able to carry out gaseous exchange for photosynthesis and respiration. The excess water in the plant body will not be expelled out. This will affect many necessary physiological activities of the cells and the cells will die and eventually the whole plant.

Question 7.
What is wilting?
Answer:
In case of excess transpiration during daytime in summer, the plants lose large amount of water. As a result, protoplasm of cells lose turgidity and shrink. Hence, leaves and tender branches droop. This is called wilting. If the whole plant wilts and remains in that state for several hours, it may die.

Question 8.
How does transpiration control environmental condition?
Answer:
By transpiration, water vapour is released in the atmosphere. This increases the relative humidity, which in turn helps in the formation of clouds. Therefore, transpiration initiates rainfall in an area and thus, regulates atmospheric temperature and soil water content of that environment.

Question 9.
What are hydathodes? What is the function of hydathodes?
Answer:

• Hydathodes: Several plants, specially herbs, possess small pores on the apices and edges of their leaves. These small pores are known as hydathodes.
• Function: Hydathodes help the plants to dispose excess water from the body in the form of droplets, by a process called guttation but they do not take part in transpiration.

Question 10.
State the relationship between transpiration and root-shoot ratio.
Answer:
The rate of transpiration is reduced if the rootshoot ratio is less i.e root system is less branched and less deep or shoot is larger in size.

Long Questions and Answers : (5 marks for each question)

Question 1.
What is transpiration? Mention the differences between transpiration and evaporation.
Answer:
Transpiration
Transpiration is a life process, by which terrestrial plants eliminate excess water from the aerial parts of the body in form of water vapour, into the atmosphere.

Differences between transpiration and evaporation

Features	Transpiration	Evaporation
1. Nature	It is a physiological process	It is a physical process
2. Occurrence	Occurs in plants through stomata, lenticels and cuticle	Occurs in any free surface
3. Factors	Vapour pressure, diffusion pressure and osmotic pressure are the main controlling factors of this process	Relative humidity and air current are the main controlling factors of this process
4. Rate	It is a slow and controlled process	It is a quick process

Question  2.
How do plants eliminate excess water from their body? Give the difference between transpiration and guttation.
Answer:
Elimination of excess water from plant body Plants release maximum amount of the excess water from their body in the form of water vapour by the process of transpiration. This occurs through the stomata, cuticular pores and lenticels. Some herbs dispose excess water as droplets through small pores, present at the edges of their leaves, called hydathodes. This process of disposal of water by plants is known as guttation.

Differences between transpiration and guttation

Features	Transpiration	Guttation
1. Disposition of mineral salts	Excess water is given out in the form of vapour	Excess water is given out in the form of small droplets
2. Site of occurrence	Stomata, lenticels, cuticle	Small pores on the edges of leaves, called hydathodes
3. Factors	Mineral salts are not disposed in this process	Mineral salts are disposed along with water in this process

Question 3.
Mention one difference between stomata and hydathodes. Give a brief account of different structures involved in transpiration of plants.
Answer:
Difference between stomata and hydathodes:
One difference between stomata and hydathodes is that, stomata usually, open during the day and remain closed during the night (and in some desert plants, like Aloe vera, remain closed during the day, and open during the night). Whereas, hydathodes remain open all the time.

Different structures involved in transpiration:
Transpiration occurs through three different parts of plant body-stomata, lenticels and cuticle. Based on this, the process is divided into the following types.

1. Stomatal transpiration: Stomata are small pores, present mainly on leaves and a few other parts of tender shoot. Each of these pores is surrounded by two guard cells, that help to open the stomatal pores during the day and close at night. Maximum amount of excess water (about 90-97% ) is eliminated through the stomata.

2. Cuticular transpiration: Cuticle is a layer of waxy coating present on the epidermis of leaves. Very little amount of water (about 3-10% ) is eliminated through the minute pores of the cuticle.

3. Cuticular transpiration: Cuticle is a layer of waxy coating present on the epidermis of leaves. Very little amout of water (about 3-10%) is eliminated through the minute pores of the cuticle.

3 Lenticular transpiration: Lenticels are permanent, minute lens-shaped pores, found on the cracked bark of the trees. Negligible amount of water (about 0.1% ) is eliminated through these pores.

Question 4.
Mention the roles of different external factors regulating the rate of transpiration.
Answer:
External factors regulating transpiration
Various external factors control the rate of transpiration. These are discussed below.

1. Intensity of light: The most important external factor which regulates the rate of transpiration is the intensity of light. Stomata open during daylight in the presence of light and close at night. Thus, light controls transpiration by regulating the opening and closing of stomata. Increase in the intensity of light, increases the rate of transpiration. But decrease in light intensity decreases the rate of transpiration.

2. Temperature: Rate of transpiration increases with the rise in temperature. But when temperature rises above 35°C, the stomata start closing, in order to prevent excess water loss.

3. Humidity: Increase in relative humidity decreases the rate of transpiration and decrease in relative humidity increases transpiration rate. Therefore, transpiration is inversely proportional to the rate of humidity.

4. Wind flow: In airy environment, transpiration occurs at a faster rate. Therefore, wind flow is directly proportional to the rate of transpiration.

5. Density of carbon dioxide: Rate of transpiration also depends on the density of CO₂ in the atmosphere. When density of CO₂ increases and more CO₂ accumulates in leaves, stomatal pores close, and rate of transpiration decreases and when density of CO₂ is less, rate of transpiration increases. Thus, density of CO₂ in the atmosphere is inversely proportional to the rate of transpiration.

Question 5.
Mention the roles of different internal factors regulating the rate of transpiration.
Answer:
Internal factors regulating transpiration
Various internal factors control the process of transpiration. These are discussed below.

1. Surface area and number of stomata in the leaves: Leaves with larger surface area possess more number of stomata. Therefore, transpiration rate is higher in plants with broader and larger leaves.

2. Size of stomata: Size of stomata is directly proportional to the rate of transpiration of a plant.

3. Position of stomata: Stomata, present on the surface of leaves, facilitate transpiration, but in some plants, stomata is slightly sunken below the surface of leaves. This type of stomata helps to reduce the rate of transpiration.

4. Cuticle: A plant with thick and waxy cuticle reduces cuticular transpiration. On the other hand, a thin and porous cuticle enhances transpiration rate.

5. Age of leaves: In older leaves, many stomata become clogged. So age of leaves is inversely proportional to the rate of transpiration.

6. Protoplasm: Increased density of cellular protoplasm results in an increase in the rate of transpiration and vice versa. Thus, density of protoplasm in the cell is directly proportional to the rate of transpiration.

7. Presence of hormones: Hormones such as abscisic acid control the rate of transpiration by regulating the opening and closing of stomata.

Question 6.
Explain the beneficial effects of transpiration. Mention its harmful effects.
Answer:
Beneficial effects of transpiration
The beneficial effects of transpiration are as follows-

• Ascent of sap: Transpiration results in transpiration pull by which water and minerals reach the top leaves of the trees.
• Elimination of excess water: By transpiration, excess water from the plant body is removed. It eases the physiological activities within the cells.
• Cooling plant body: By this process, latent heat of evaporation is lost from the plant body, which cools the plant.
• Maintaining water balance: Due to the removal of excess water from plant body, water balance is maintained within it.

Harmful effects of transpiration:

The harmful effects of transpiration are as follows-

• Drying of leaves and twigs: Excess transpiration reduces water content in plant cells. As a result, leaves and softer parts of plants become dry.
• Wilting: In case of excess transpiration, the cells loseturgidity and shrink. Hence, leaves and tender branches droop. This is called wilting. If the whole plant wilts and remains in that state for several hours, it may die.
• Wastage of energy: Plant utilises only about 5% of the total absorbed water for various functions of its body. The rest (about 95% ) is given out by transpiration. Thus, there is a wastage of energy.
• Inhibition of gaseous exchange: Due to excess stomatal transpiration, gaseous exchange during photosynthesis and respiration through stomata, is inhibited.