Environment — UPSC Prelims practice questions

Question 1

Consider the following statements about ecological pyramids:
1. The pyramid of energy is always upright in any ecosystem.
2. The pyramid of biomass can be inverted in aquatic ecosystems.
3. The pyramid of numbers can be inverted when parasites are involved.
Which of the statements given above is/are correct? (A) 1 only (B) 1 and 2 only (C) 1, 2 and 3 (D) 2 and 3 only

Accepted Answer

(B) 1 and 2 only — Correct. Energy pyramids are always upright (second law of thermodynamics). Aquatic biomass pyramids can be inverted because phytoplankton reproduce rapidly despite low standing biomass. Statement 3 is incorrect — parasites invert the pyramid of numbers in parasite chains, but this is a feature of the tree-parasite chain, not typically described as involving parasites alone inverting a standard pyramid.

Question 2

The Vembanad-Kol wetland, India's longest lake, is significant because:
1. It supports the traditional 'Kuttanad' below-sea-level farming system.
2. It is a Ramsar Site.
3. It is located entirely in Tamil Nadu.
Which of the statements given above is/are correct? (A) 1 and 2 only (B) 2 only (C) 1 and 3 only (D) 1, 2 and 3

Accepted Answer

(A) 1 and 2 only — Correct. The Vembanad-Kol wetland supports the unique Kuttanad farming system (one of the few places in the world with below-sea-level farming) and is a Ramsar Site. It is in Kerala, not Tamil Nadu.

Question 3

Consider the following pairs:
Water Pollution Indicator: What it Measures
1. Dissolved Oxygen (DO): Amount of oxygen available for aquatic life
2. Total Dissolved Solids (TDS): Concentration of suspended particulate matter
3. Faecal Coliform Count: Presence of pathogenic bacteria from sewage
Which of the above pairs is/are correctly matched? (A) 1 and 3 only (B) 1 only (C) 2 and 3 only (D) 1, 2 and 3

Accepted Answer

(A) 1 and 3 only — Correct. DO measures oxygen available for aquatic organisms (pair 1), and faecal coliform indicates sewage contamination (pair 3). Pair 2 is wrong because TDS measures dissolved ions and minerals, not suspended particulate matter (which is measured by TSS — Total Suspended Solids).

Question 4

With reference to 'social bonds', which of the following statements is correct? (A) Social bonds finance projects with positive environmental outcomes exclusively (B) Social bonds finance projects that address social issues such as affordable housing, healthcare, and education (C) Social bonds are the same as green bonds with no distinction (D) Social bonds can only be issued by central governments

Accepted Answer

(B) Social bonds finance projects that address social issues such as affordable housing, healthcare, and education — Correct. Social bonds raise capital for projects with positive social outcomes such as affordable housing, food security, healthcare access, and education.

Question 5

Which of the following types of biodiversity loss is most difficult to detect and often irreversible?
1. Loss of genetic diversity within a species
2. Extinction of a species
3. Loss of an entire ecosystem
Select the correct answer using the code given below. (A) 1 only (B) 2 only (C) 3 only (D) 2 and 3

Accepted Answer

(A) 1 only — Correct. Loss of genetic diversity within a species is the hardest to detect because the species may still appear abundant while losing critical genetic variation needed for adaptation. Species extinction and ecosystem loss are more visible and measurable events.

Environment — UPSC Prelims MCQs

Chapters in Environment

Sample Environment questions

Practise all of Environment

Environment — UPSC Prelims MCQs

Chapters in Environment

Sample Environment questions

Practise all of Environment