Question

Which one of the following is not a bio fertilizer?

• A. Mycorrhiza
• B. Agrobacterium
• C. Rhizobium
• D. Nostoc

Answer 1

The correct option is C

Rhizobium

The correct option is Option C.

Explanation for the correct option :

1. Agrobacterium is a bacterium used as a natural vector to transfer genes to the pants.
2. It causes tumours in plants. It does not increase the nutritional supply or growth of the plant; hence, it is not a bio fertilizer.

Explanation for the incorrect options :
Option A:
Mycorrhiza is a bio fertilizer because it supplies water and nutrients to the host plant.

Option B:
Rhizobium is a bio fertilizer because it helps fix large amounts of nitrogen for the plant.

Option D:
Nostoc is a nitrogen-fixing bacteria for plants. It supplies plants with nitrogen and thus acts as a bio fertilizer.

Final Answer: Rhizobium is not a bio-fertilizer.