1. An organism’s niche is
(A) The way the organism uses the range of physical and biological conditions in which it lives.
(B) All the biological and physical factors in the organism’s environment.
(C) The function role played by the organism where it lives.
(D) The range of temperature that the organism needs to live.

2. The pyramid of biomass is invented in
(A) Forest ecosystem
(B) Greenland ecosystem
(C) Aquatic ecosystem
(D) All of the above

3. Largest amount of fresh water is present in
(A) Lakes
(B) Rivers
(C) Glaciers
(D) Polar Ice

4. A threatened species is
(A) Only endangered species
(B) Only vulnerable species
(C) Only rare species
(D) all of the above

5. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R).
Assertion (A): Animals adopt various strategies to survive in hostile environment.
Reason (R): Praying mantis is green in color which emerges with plant foliage.

Choose the correct code:
(A) Both (A) and (R) are true, with (R) being the correct explanation of (A).
(B) Both (A) and (R) are true but (R) is not correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) Both (A) and (R) are false.

6. The evolution of genetic resistance to antibiotics among disease-carrying bacteria is an example of
(A) Directional natural selection
(B) Stabilizing natural selection
(C) Diversifying natural selection
(D) Convergent natural selection

7. The Keystone predator species maintain diversity in a community by
(A) Preying on community’s dominant species
(B) Allowing immigration of other predators
(C) Competitively excluding other predators
(D) Coevolving with their prey

8. Which of the following is not an external factor controlling an ecosystem?
(A) Climate
(B) Topography
(C) Parent material forming soil
(D) Microbes

9. Which of the following food chain is correct?
(A) Phytoplankton → Zooplankton → Turtle → Crabs
(B) Phytoplankton → Zooplankton → Crab → Turtle
(C) Turtle → Crab → Zooplankton → Phytoplankton
(D) Zooplankton → Turtle → Crab → Phytoplankton

10. Which of the following is not categorized as an internal factor of an ecosystem?
(A) Decomposition
(B) Succession
(C) Root competition
(D) Bedrock

11. Two species cannot remain in same place according to
(A) Allen’s law
(B) Gause hypothesis
(C) Doll’s rule
(D) Weismann’s theory

12. Identify the correct pair:
(A) Ecotope – Transition between two ecosystems.
(B) Edaphic – Saline soil
(C) Heliophytes – Photophilic plants
(D) Ecotone – Particular type of soil

13. Based on the number arrange the following group of endemic vertebrate species of India in descending order:
(i) Mammals
(ii) Birds
(iii) Reptiles
(iv) Amphibians

Choose the correct answer from the following:
(A) Amphibians, Reptiles, Birds and Mammals.
(B) Reptiles, Amphibians, Birds and Mammals.
(C) Mammals, Birds, Amphibians and Reptiles.
(D) Birds, Mammals, Reptiles and Amphibians

14. Freshwater ecosystems are nutritionally limited by
(A) Phosphorous and Iron
(B) Phosphorous and Carbon
(C) Iron and Nitrogen
(D) Nitrogen and Calcium

15. ‘Threshold of Security’ refers to the population level at which
(A) Parasites damage the host body but do not cause immediate mortality.
(B) Predators no longer find it profitable to hunt for the prey species.
(C) Functional response of the predator is very high.
(D) The balance between parasite and host is disturbed as the host produces antibodies.