Nodules with nitrogen-fixing bacteria are present in

1. mustard
2. wheat
3. gram
4. cotton

Correct Answer: (c) gram

Explanation:

Nodules with nitrogen-fixing bacteria are present in leguminous plants such as gram.

Root nodules are extra lobes of certain plants such as peas and beans in which nitrogen-fixing bacteria are found.

Bacteria in these root nodules convert the atmospheric nitrogen into nitrates which the plants can utilize. The plants use this nitrogen to synthesize proteins and other materials.