Explore topic-wise MCQs in Biology.

This section includes 286 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.

1.

In the context of ecosystem productivity marine upwelling zones are important as they increase the marine productivity by bringing the
1. Decomposer micro - organisms to the surface
2. Nutrient to the surface
3. Bottom dwelling organisms to the surface
Which of the statements given below are correct ?

A. 1 & 2
B. 2 only
C. 2 and 3
D. 3 only
Answer» D. 3 only
Discussion
2.

Environmental friendliness of a vehicle could be measured by the amount of pollutants it emits per passenger per kilometre travelled. Rate the environmental friendliness (1=best & 4 = Worst) of the following vehicles as per this criterion :
Car : scooter : bus : bicycle

A. 4 : 3 : 2 : 1
B. 2 : 3 : 4 : 1
C. 3 : 2 : 4 : 1
D. 4 : 2 : 3 : 1
Answer» B. 2 : 3 : 4 : 1
Discussion
3.

In a mountaenous terrain, rich biodiversity is found in areas located at

A. Lower latitudes and higher altitudes
B. Higher latitudes and lower altitudes
C. Lower latitudes and lower altitudes
D. Higher latitudes and higher altitudes
Answer» D. Higher latitudes and higher altitudes
Discussion
4.

Consider the following statements
1. Biodiversity is normally greater in the lower latitudes as mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.
Which of the statements given above is are correct ?

A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 and 2
Answer» D. Neither 1 and 2
Discussion
5.

The Secretariat of the conventions on Biological Diversity, coordinating the International year of
Biodiversity compaign was based in

A. Italy
B. London
C. Toronto
D. Montreal
Answer» E.
Discussion
6.

Consider the following Statements :
1. An increase in tropospheric oznoe concentration has a warming effect on earth
2. A decrease in stratospheric ozone concentration has a cooling effect on earth
Which of the above statements is/are true ?

A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 nor 2
Answer» D. Neither 1 nor 2
Discussion
7.

Consider the following list of factors :
1. Dispersal
2. Rainfall
3. Mineral deposits
4. Competition
5. Temperature
Which of the factors listed above are most significant in determining the fact that belts of vegetation at successively higher latitudes ?

A. 1 and 3
B. 3 and 5
C. 2 and 4
D. 2 and 5
Answer» E.
Discussion
8.

Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, bu a lot of it does not remain in the lower atmosphere because of
1. Its escape into the outer strato-sphere.
2. The photosynthesis by phyto-plankton in the oceans.
3. The trapping of air in the polar ice caps.
Which of the statements given above is / are correct ?

A. 1 and 2
B. 2 only
C. 2 and 3 only
D. 3 only
Answer» D. 3 only
Discussion
9.

In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the
1. decomposer micro-organisms to the surface.
2. nutrients to the surface.
3 bottom-dwelling organisms to the surface
Which of the statements given above is/are correct ?

A. 1 and 2
B. 2 only
C. 2 and 3
D. 3 only
Answer» C. 2 and 3
Discussion
10.

There is a concern over the increase in harmful algae blooms in the sea waters of India. What could be the causative factors for this phenomenon ?
1. Discharge of nutrients from the estuaries.
2. Run-off from the land during the monsoon.
3. Upwelling in the seas.
Select the correct answer from the codes given below

A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3
Answer» C. 2 and 3 only
Discussion
11.

Biodiversity forms the basis for human existence in the following ways :
1. Soil formation
2. Prevention of soil erosion
3. Recycling of waste
4. Pollination of crops
Select the correct answer using the codes given below:

A. 1, 2 and 3 only
B. 2, 3 and 4 only
C. 1 and 4 only
D. 1, 2, 3 and 4
Answer» E.
Discussion
12.

By 2100 AD, global temperature is expected to rise by about 2 C and consequently, the sea level by about 50 cm from the present level. How is a rise in temperature expected to increase the level of the sea ?

A. By expanding ocean water
B. By melting mountain glaciers
C. By causing ice sheets of Antarctica and Greenland to melt and slide into the oceans
D. All of the above
Answer» E.
Discussion
13.

CFC (chloro-fluoro-carbons) are greenhouse gases that have caused a rise of 0.3 C in the global temperatures in the past century. Name the CFC that is used in refrigerators.

A. Carbon dioxide
B. Freon
C. Methane
D. Ammonia
Answer» C. Methane
Discussion
14.

Name the gas released from landfills, decaying organic matter under shallow water in marshes and bogs, flooded paddy fields, by ruminant animals & termites and by the burning of biomass. A molecule of this gas has 21 times more global warming potential than a molecule of Co2.

A. Sulphur dioxide
B. Methane
C. Ammonia
D. Nitrous Oxide
Answer» C. Ammonia
Discussion
15.

The rich biodiversity of India is under severe threat due to
1. Habitat destruction
2. Degradation
3. Fragmentation
4. Over exploitation

A. 1, 2, 3, 4
B. 2, 3, 4
C. 1, 3, 4
D. 1, 2, 3
Answer» B. 2, 3, 4
Discussion
16.

The ecological foot print is a measure of ecological inpact of
1. comsumption of food, forest products and other resources
2. deforestation
3. land use for roads, buildings, power plants and garbage dumps.

A. 1 and 3
B. 2 only
C. 1, 2, and 3
D. 3 only
Answer» D. 3 only
Discussion
17.

Consider the following :
1. Carbon dioxide
2. Oxides of Nitrogen
3. Oxides of Sulphur
Which of the above is / are the emission / emissions from coal combustion at thermal power plants ?

A. 1 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3 only
Answer» E.
Discussion
18.

A study of a meadow ecosystem revealed the following tropic relationships :
sweet clover - grasshoppers - toads - snakes. The primary producer (s) in the meadow is (are) .............

A. Sweet clover
B. Grasshoppers
C. Toads
D. Snakes
Answer» B. Grasshoppers
Discussion
19.

Read the two statements A and B
Statement (A) : Diversity observed in the entire geographical area is called gamma diversity.
Statement (B) : Biodiversity decreases from high altitude to low altitude Identify the correct choice from these given below :

A. Statement A is Correct, B is wrong
B. Statement B is Correct, A is wrong
C. Both the statements A and B are correct
D. Both the statements A and B are wrong.
Answer» B. Statement B is Correct, A is wrong
Discussion
20.

The "Red Data books" published by the International Union for Conservation of Nature and Natural Resources (IUCN) contain lists of
1. Endemic plant and animal species present in the biodiversity hotspots.
2. Threatened plant and animal species.
3. Protected sited for conservation of nature and natural resource in various countries.
Select the correct answer using the codes given below

A. 1 and 3
B. 2 only
C. 2 and 3
D. 3 only
Answer» C. 2 and 3
Discussion
21.

Biodiversity hotspots in India are
1. Eastern Ghat
2. Eastern Himalayas
3. Andaman and Nicobar islands
4. Western Ghat
Codes

A. 1, 2
B. 2, 3, 4
C. 2, 3
D. 2, 4
Answer» E.
Discussion
22.

Along a food chain, the role of .............is to help return or recycle the primary chemical compounds of organisms back to the chain : carbon, hydrogen, nitrogen, and other minor compounds.

A. Decomposers (bacteria, fungus)
B. Consumers (lions, tigers)
C. Prey (deer, water buffaloes)
D. Producers (plants, trees)
Answer» B. Consumers (lions, tigers)
Discussion
23.

A term biotype means

A. All individuals having same Phenotype
B. All individuals having same genotype
C. All individual with different phenotype
D. All individuals with different genotype
Answer» B. All individuals having same genotype
Discussion
24.

Mangroves are salt-tolerant forest ecosystems. Name the largest mangrove forests in the world that constitute 7% of the worlds mangroves, house a variety of wildlife sanctuaries, and are also a potential site to harness tidal energy.

A. The Sunderbans in West Bengal
B. Muisue Forests in Eucador
C. The Mekong Delta in Vietnam
D. None of these
Answer» B. Muisue Forests in Eucador
Discussion
25.

During the growth of a tomato plant from a seed, it increases considerably in biomass. Which of the following materials, obtained from the environment, are necessary for the growth and increase in biomass ?

A. Carbon dioxide and water.
B. Carbon dioxide, oxygen, and nitrogen.
C. Water, nitrate, and methane.
D. Water, carbon dioxide, and mineral salts.
Answer» E.
Discussion
26.

The 1987 Montreal Protocol was signed for which of the following reasons ?

A. To phase out the use of CFC's, found to be causing depletion of the ozone layer
B. To ban nuclear testing in tropical oceans
C. To begin converting from fossil fuel use to more renewable energy sources to reduce the anthropogenic greenhouse effect
D. To stop the global trade in products made from endangered tigers
Answer» B. To ban nuclear testing in tropical oceans
Discussion
27.

Which of the following is not a major positive feedback mechanism in which the activity of humans to increase global climate temperatures leads to an even further increase ?

A. Tropical deforestation cause warming and drying so that remaining forests begin to decline
B. Global warming causes snow to melt in polar regions and therefore increases global albedo
C. Global warming causes increased rainfall, plant growth and photosynthesis
D. Global warming causes increased CO
E. release from biomass decomposition
Answer» D. Global warming causes increased CO
Discussion
28.

Regarding "carbon credits", which one of the following statements is not correct ?

A. The carbon credit system was ratified in conjunction with the Kyoto Protocol
B. Carbon credits are awarded to countries or groups that have reduced greenhouse gases below their emission quota
C. The goal of the carbon credit system is to limit the increase of carbon dioxide emission
D. Carbon credits are traded at a price fixed from time to time by the United Nations Environment Programme
Answer» E.
Discussion
29.

In your opinion, which is the most effective way to conserve the plant diversity of an area ?

A. By creating biosphere reserve
B. By creating botanical gardens
C. By developing seed bank
D. By tissue culture method
Answer» B. By creating botanical gardens
Discussion
30.

Which one of the following is a pair of endangered species ?

A. Garden lizard and Maxican poppy
B. Rhesus monkey and Sal tree
C. Indian peacock and Carrot grass
D. Hornbnill and Indian Aconite
Answer» E.
Discussion
31.

Which of the following lists include only abiotic environmental factors ?

A. Food, temperature, fire, wind
B. Soil minerals, oxygen level, light, predators
C. Wind, rainfall, temperature, soil minerals
D. Light, food, predators, competitors
Answer» D. Light, food, predators, competitors
Discussion
32.

Which of the following is an example of secondary succession ?

A. Appearance of mosses and weeds on an exposed rock fence
B. Abandoned farm field covered with weeds and shrubs.
C. Former pond now supporting growth of shrubs and trees
D. Establishment of plants on a newly-formed island
Answer» C. Former pond now supporting growth of shrubs and trees
Discussion
33.

Epiphytes are found in those places where

A. Temperature is very low
B. Concentration of oxygen is high
C. Rain fall occur all over year
D. Rain fall occur according to season
Answer» D. Rain fall occur according to season
Discussion
34.

Human body gets citric acid from which of the following resources ?

A. Lime
B. Lemon
C. Guava
D. (a), (b) and (c) All
Answer» E.
Discussion
35.

Producer of an ecosystem

A. Convert organic compound into inorganic compound
B. Convert solar energy into chemical energy
C. Use chemical energy
D. Release energy
Answer» C. Use chemical energy
Discussion
36.

The term ecology is first given by

A. Robbert brown
B. Aristotal
C. Khurana
D. Reiter
Answer» E.
Discussion
37.

Study of inter relationship between living organism and their environment is called

A. Plant Geography
B. Ecology
C. Plant social science
D. Ecosystem
Answer» C. Plant social science
Discussion
38.

Removal of top soil by air & water is called

A. Erosion
B. Fossilisation
C. Calcination
D. Salination
Answer» B. Fossilisation
Discussion
39.

In an ecosystem which one show one way passage

A. Free energy
B. Carbon
C. Nitrogen
D. Potassium
Answer» B. Carbon
Discussion
40.

Energy transfer from organism to organism in a natural community develops

A. Biological control
B. Food chain
C. Food web
D. Pyramid of energy
Answer» D. Pyramid of energy
Discussion
41.

Two components of ecosystem are

A. Herb and shurb
B. Abiotic and biotic
C. Frog and Human
D. Plant and animal
Answer» C. Frog and Human
Discussion
42.

Which one of the following is abiotic component of ecosystem

A. Bacteria
B. Chlorella
C. Water
D. Human
Answer» D. Human
Discussion
43.

In a ecosystem the largest number is that of

A. Primary producer
B. Primary consumer
C. Secondary consumer
D. Decomposer
Answer» B. Primary consumer
Discussion
44.

Which of the following is correct energy flow in a ecosystem

A. Producer Carnivorous Herbivorous Decomposer
B. Producer Herbivorous Carnivorous Decomposer
C. Herbivorous Carnivorous Producer Decomposer
D. Herbivorous Producer Carnivorous Decomposer
Answer» C. Herbivorous Carnivorous Producer Decomposer
Discussion
45.

Long roots system are found in xerophytes, because

A. It give mechanical support to plant
B. To absorb water situated deep inside earth
C. High temperature of soil cause growth in root
D. How temperature during night cause growth on root
Answer» C. High temperature of soil cause growth in root
Discussion
46.

Which one of the following harmful elements tobacoo exists in tobacoo ?

A. Morphine
B. Haronie
C. Nicotine
D. None of these
Answer» D. None of these
Discussion
47.

Ecosystem is

A. Always open
B. Always closed
C. Both open and closed depending upon community
D. Both open and closed depending upon biomass
Answer» D. Both open and closed depending upon biomass
Discussion
48.

In a food chain energy transfer

A. From river to earth
B. Lower lattitude to higher lattitude
C. From one organism to other organism
D. None of the above
Answer» D. None of the above
Discussion
49.

An association of individuals of different species living in the same habitat having functional interactions is

A. Population
B. Ecological niche
C. Biotic community
D. Ecosystem
Answer» D. Ecosystem
Discussion
50.

Path of energy flow in an ecosystem is

A. Herbivores Producers Carnivores Decomposer
B. Herbivorous Carnivorars Producers Decomposer
C. Producer Carnivoras Herbivarous Decomposer
D. Producer Herbivarous Carnivores Decomposer
Answer» E.
Discussion