UPSC CSE Prelims
Question 88
What would happen if phytoplankton of an ocean is completely destroyed for some reason?
- The ocean as a carbon sink would be adversely affected.
- The food chains in the ocean would be adversely affected.
- The density of ocean water would drastically decrease.
Select the correct answer using the codes given below:
View correct answer and explanation
Correct answer: A
Correct Option: A
Explanation: Marine phytoplankton remove dissolved CO₂ through photosynthesis and form the base of many ocean food webs.
Statement/Item-wise Analysis:
1: Correct - Destroying them diminishes photosynthetic carbon uptake and the biological carbon pump.
2: Correct - Zooplankton, fish and other marine organisms depend directly or indirectly on them for food.
3: Incorrect - Complete loss would not directly produce a drastic reduction in seawater density.
Option-wise Analysis:
A: Correct - includes exactly the valid statements/items and excludes the invalid ones.
B: Incorrect - omits correct item 1.
C: Incorrect - includes incorrect item 3; omits correct items 1, 2.
D: Incorrect - includes incorrect item 3.