UPSC Previous Year Question | Prelims GS | 2022

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?

  1. The water cycle in wetlands involves surface runoff, subsoil percolation and evaporation.
  2. Algae form the nutrient base upon which fish, crustaceans, molluscs, birds, reptiles and mammals thrive.
  3. Wetlands play a vital role in maintaining sedimentation balance and soil stabilization.
  4. Aquatic plants absorb heavy metals and excess nutrients.

Answer

Correct Answer

Aquatic plants absorb heavy metals and excess nutrients.

Explanation

Wetlands function as the Earth's 'kidneys' because aquatic plants absorb and filter out heavy metals and excess nutrients, purifying water much like kidneys filter blood.

Topics: environment, heavy metals and nutrients, water purification, wetland ecology