Question

Assertion — Rhizobium lives in the root nodules of leguminous plants.
Reason — It fixes nitrogen through a symbiotic relationship.

• A. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
• C. If Assertion is correct but Reason is incorrect.
• D. If Assertion is incorrect but Reason is correct.

Answer 1

The correct option is A

If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

Option (A):
Assertion statement:

1. Rhizobium is a type of bacteria which is present in the root nodules of the leguminous plants.
2. These bacteria form a symbiotic relationship with the roots.

Reason statement:

1. Nitrogen cannot be directly taken by plants and animals and therefore fixation of nitrogen is required.
2. Bacteria like Rhizobium convert the atmospheric nitrogen into usable forms like ammonia, nitrates and nitrites.
3. These are directly absorbed by the plant from the soil.

Final answer: Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.