Question

Given below are two statements
Statement I: Most of the marine invertebrates are osmoconformers
Statement II: Osmoconformers are organisms that have physiological mechanisms to control the salt content of their internal fluid.
In light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

- Osmoconformers: Body osmolarity = Environment osmolarity (mostly marine invertebrates).
- Osmoregulators: Body osmolarity is kept constant regardless of the environment (most teleost fishes).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Osmoregulation is the physiological process by which organisms maintain the water and salt balance of their internal body fluids relative to the surrounding environment.

Step 2: Detailed Explanation:
- Statement I: Marine invertebrates generally live in a highly stable osmotic environment (open ocean seawater).
Most of these invertebrates do not maintain an osmotic gradient; their body fluids remain isotonic to seawater.
Hence, they are classified as osmoconformers.
Therefore, Statement I is correct.
- Statement II: Osmoconformers do not actively regulate their internal osmolarity.
Instead, their internal fluid osmolarity passively matches that of the surrounding water.
They lack physiological mechanisms to control the salt content different from the environment (unlike osmoregulators, which actively control internal salinity).
Therefore, Statement II is incorrect.

Step 3: Final Answer:
Since Statement I is correct but Statement II is incorrect, the correct option is (C).