PREVIOUS YEAR QUESTIONS (PRELIMS)
Q.1 ) “If rainforests and tropical forests are the lungs of the Earth, then surely wetlands function as its kidneys.” Which one of the following functions of wetlands best reflects the above statement? UPSC (2022)
- The water cycle in wetlands involves surface runoff, subsoil percolation and evaporation.
- Algae form the nutrient base upon which fish, crustaceans, molluscs, birds, reptiles and mammals thrive.
- Wetlands play a vital role in maintaining sedimentation balance and soil stabilization.
- Aquatic plants absorb heavy metals and excess nutrients.
Answer: D
Explanation:
- The analogy compares wetlands to kidneys because kidneys filter toxins and maintain balance in the body.
- Similarly, wetlands remove excess nutrients and pollutants (including heavy metals) from water, purifying it, just as kidneys purify blood.
- This ecological service of wetlands is critical to maintaining water quality and ecosystem health.
Hence, the function that best reflects the “kidneys of the Earth” role is:
Absorbing heavy metals and excess nutrients.
Q.2) The process of using microbes to treat areas of land or sea that have been contaminated by pesticides, oil or solvents is known as: CAPF (2016)
- Eutrophication
- Nitrification
- Ammonification
- Bioremediation
Answer: D
Explanation:
- Bioremediation:
It refers to the use of microorganisms (bacteria, fungi, algae) to degrade, detoxify, or transform pollutants in soil, water, or air into harmless products.- Example: Oil spill cleanup in oceans using oil-degrading bacteria.
- Advantage: Cost-effective and eco-friendly.
- Eutrophication: Nutrient enrichment in water bodies causing algal blooms and oxygen depletion.
- Nitrification: Conversion of ammonia into nitrate by nitrifying bacteria.
- Ammonification: Decomposition of organic nitrogen into ammonia.
Q.3) Which of the following Ramsar Wetland sites is not situated in any of the Union Territories of India? CDS-II (2024)
- Hokera Wetland
- Point Calimere Wildlife and Bird Sanctuary
- Tso Moriri Lake
- Wular Lake
Answer: B
Explanation:
- Point Calimere Wildlife and Bird Sanctuary is located in the Nagapattinam district of Tamil Nadu, which is a state, not a Union Territory.
- The others are located in Union Territories:
- Hokera Wetland: Jammu & Kashmir (now UT of J&K).
- Tso Moriri Lake: Ladakh (UT).
- Wular Lake: Jammu & Kashmir (UT).