Prelims Questions: Biosphere & Working of Ecosystem | Environment for UPSC CSE PDF Download

Prelims Questions

Food Chain

Q1. Which one of the following is the correct sequence of a food chain?(2014)
(a) Diatoms-Crustaceans-Herrings

(b) Crustaceans-Diatoms-Herrings

(c) Diatoms-Herrings-Crustaceans

(d) Crustaceans-Herrings-Diatoms

Correct Answer: (a)

Q2. With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms? (2013)
1. Virus

2. Fungi

3. Bacteria

Select the correct answer using the codes given below:
(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Correct Answer: (b)

Q3. With reference to food chains in ecosystems, consider the following statements: (2013)
1. A food chains illustrates the order in which a chain of organisms feed upon each other.
2. Food chains are found within the populations of a species.
3. A food chain illustrates the numbers of each organism which are eaten by others.

Which of the statements given above is/are correct?
(a) 1 only

(b) 1 and 2 only

(c) 1, 2 and 3

(d) None

Correct Answer: (a)
 

Ecosystem

Q4. Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity? (2013)
(a) Oceans, lakes, grasslands, mangroves

(b) Mangroves, oceans, grasslands, lakes

(c) Mangroves, grasslands, lakes, oceans

(d) Oceans, mangroves, lakes, grasslands

Correct Answer: (c)

Q5. In the grasslands, trees do not replace the grasses as a part of an ecological succession because of- (2013)
(a) insects and fungi

(b) limited sunlight and paucity of nutrients

(c) water limits and fire

(d) None of the above

Correct Answer: (c)

Q6. What would happen if the phytoplankton of an ocean is completely destroyed for some reason? (2012)
1. The ocean as a carbon sink would be adversely affected.
2. The food chains in the ocean would be adversely affected.
3. The density of ocean water would drastically decrease.

Select the correct answer using the codes given below:
(a) 1and 2 only

(b) 2 only

(c) 3only

(d) 1, 2 and 3

Correct Answer: (a)
 

Q7. The Millennium Ecosystem Assessment describes: The following major categories of ecosystem services—provisioning, supporting, regulating, preserving and cultural. Which one of the following is a supporting service? (2012)
(a) Production of food and water

(b) Control of climate and disease

(c) Nutrient cycling and crop pollination

(d) Maintenance of diversity

In the context of ecosystem productivity, marine upwelling zones are important as they increase marine productivity by bringing the-(2011)
1. Decomposer microorganisms 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

Correct Answer: (c)

Q8. If a tropical rain forest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because: (2011)
(a) The soil of rain forest is deficient in nutrients

(b) Propagules of the trees in a rain forest have poor viability

(c) The rain forest species are slow growing

(d) Exotic species invade the fertile soil of rain forest

Correct Answer: (a)

Q9. In the context of ecosystem productivity, marine upwelling zones are important as they increase marine productivity by bringing the-(2011)
1. Decomposer microorganisms 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

Correct Answer: (b)

Ecology

Q10. Consider the following organisms: (2013)
1. Agaricus
2. Nostoc
3. Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers?
(a) 1 and 2

(b) 2 only

(c) 2 and 3

(d) 3 only

Correct Answer: (b)

Q11. Which one of the following terms describes not only the physical space occupied by an organism but also its functional role in the community of organisms? (2013)
(a) Ecotone

(b) Ecological niche

(c) Habitat

(d) Home range Ecology

Correct Answer: (b)

Q12. A pesticide which is a chlorinated hydrocarbon is sprayed on a food crop. The food chain is: Food crop – Rat - Snake - Hawk. In this food chain, the highest concentration of the pesticide would accumulate in which one of the following? (2010)
(a) Food crop

(b) Rat

(c) Snake

(d) Hawk
Correct Answer: (d)