Question

Assertion (A): Algae will increase the level of dissolved oxygen in the immediate environment.
Reason (R): They form the food for aquatic animals.
Identify the correct option from the following:

• (A) and (R) are true, (R) is correct explanation for (A).
• (A) and (R) are true, but (R) is not correct explanation for (A).
• (A) is true, but (R) is false.
• (A) is false, but (R) is true.

Hint:

Algae are key oxygen producers in aquatic ecosystems due to photosynthesis, not because they are food for animals. They form the base of the aquatic food chain.

Answer 1

The Correct Option is B

Let’s analyze the Assertion and Reason:

Assertion (A): Algae increase dissolved oxygen in the environment.

✔️ This is true. Algae perform photosynthesis, releasing oxygen into the water as a byproduct.

Reason (R): Algae form food for aquatic animals.

✔️ This is also true. Algae serve as primary producers and are consumed by organisms like zooplankton and fish.

Does (R) explain (A)?

❌ No. While both statements are factually correct, the reason (R) does not explain the assertion (A). Oxygen production is a result of photosynthesis, not of being a food source.

Conclusion: Both Assertion (A) and Reason (R) are true, but Reason (R) does not explain Assertion (A).

Correct Answer: (2)