Challenge Prelims V1.0 – Day 77 – GS Paper (Environment & Ecology)

1. With reference to productivity in the ecosystem, consider the following statements:

1. The gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis.
2. The secondary productivity is the available biomass for consumption to herbivores and decomposers.

Which of the statements given above is/are correct?

2. Consider the following pairs:

Type of Biodiversity: Measure of

1. Alpha diversity: Species richness in a particular ecosystem
2. Beta diversity: Total biodiversity within an entire region
3. Gamma diversity: Change in amount of species between the ecosystems.

How many of the above pairs are correctly matched?

3. Which of the following statements best describes the Chemical Oxygen Demand of a water body?

4. Consider the following types of ecological pyramids:

1. Pyramids of number
2. Pyramid of biomass
3. Pyramids of energy

How many of the pyramids given above can never be inverted in shape?

5. With reference to food chains, consider the following statements:

1. All food chains begin with autotrophs.
2. In an aquatic ecosystem, Detritus Food Chain (DFC) is the major conduit for energy flow as Grazing Food Chain (GFC) is totally absent.
3. Saprotrophs form an important part of Detritus Food Chains.

How many of the statements given above is/are correct?

6. With reference to the decomposition of organic matter in an ecosystem, consider the following statements:

1. Anaerobic conditions inhibit the process of decomposition of organic matter.
2. Decomposition involves a series of processes including fragmentation, leaching, catabolism, humification, and mineralization.

Which of the statements given above is/are correct?

7. Consider the following statements:

1. Biological Oxygen Demand (BOD) is an indicator of eutrophication in water bodies.
2. A rise in BOD means there is a presence of higher inorganic pollution in the water body.

Which of the statements given above is/are correct?

8. Which of the following statements best describes the term “Biotic potential”?

9. Consider the following statements:

1. Species evenness describes the distribution of abundance across the species in a community.
2. Species richness is the number of species within a defined region.

Which of the statements given above is/are correct?

10. A zone of gradual but continuous change from one ecosystem to another when there is no sharp boundary between the two in terms of species composition, is best described as a/an

11. Which of the following statements best describes the term bioremediation?

12. Consider the following statements:

1. Anaerobic decomposition occurs in the absence of oxygen and a lot of energy is produced in this process.
2. Anaerobic decomposition kills seeds of weeds and germs present in the waste.

Which of the statements given above is/are correct?

13. Consider the following statements with respect to the eutrophication of lakes:

1. It is a manmade process and does not occur naturally.
2. The prime contaminants for eutrophication are nitrates and phosphates.

Which of the statements given above is/are correct?

14. Consider the following statements:

Statement-I:

Most Herbicides are toxic to mammals.

Statement-II:

Herbicides become concentrated in the food web.

Which one of the following is correct in respect of the above statements?

15. With reference to ecological succession, consider the following statements:

1. Ecological succession is defined as the process in which one generation of a species replaces another without allowing other species to grow.
2. Primary succession takes place in areas that are newly exposed and essentially lifeless.

Which of the statements given above is/are correct?