Q1. Which of the following is a function of wetlands?
- Groundwater recharge and flood control
- Promote industrial development
- Increase salinity
- Reduce biodiversity
Correct Option: 1. Groundwater recharge and flood control
Explanation: Wetlands serve vital ecological roles such as groundwater recharging, flood mitigation, water purification, and providing habitat for biodiversity.
Q2. What causes the decrease in water transparency during eutrophication?
- Excess fish population
- Increase in dissolved oxygen
- Algal blooms
- High evaporation rates
Correct Option: 3. Algal blooms
Explanation: Algal blooms increase the turbidity (cloudiness) of the water, reducing transparency and blocking sunlight, which harms submerged aquatic plants.
Q3. According to the Ramsar Convention, a wetland of national importance must support at least how many water birds regularly?
- 5,000
- 10,000
- 20,000
- 50,000
Correct Option: 3. 20,000
Explanation: One of the Ramsar criteria for identifying wetlands of national importance is if it regularly supports 20,000 or more water birds.
Q4. Which of the following human activities does NOT directly contribute to eutrophication?
- Planting native trees near lakes
- Animal farming near rivers
- Discharging untreated sewage
- Use of chemical fertilizers
Correct Option: 1. Planting native trees near lakes
Explanation: Planting trees reduces runoff and filters nutrients, helping prevent eutrophication. The other options contribute nutrient loads into water bodies.
Q5. What role do riparian buffers play in reducing eutrophication?
- They increase fish breeding
- They promote urban growth
- They trap sediments and filter nutrients before reaching water bodies
- They enhance the color of water
Correct Option: 3. They trap sediments and filter nutrients before reaching water bodies
Explanation: Riparian buffers are vegetated zones along waterways that absorb and filter out nutrients and sediments from surface runoff, reducing the risk of eutrophication.