Question

Select the mismatch association among the following:

• A. Frankia – Alnus
• B. Rhodospirillum – Mycorrhiza
• C. Anabaena – Nitrogen fixer
• D. Rhizobium – Alfalfa

Answer 1

The correct option is B

Rhodospirillum – Mycorrhiza

The correct option is B.

Explanation of correct option:

1. Mycorrhiza is a mutualistic association between fungi and plant roots.
2. The fungi supply the plants with inorganic nutrients like calcium and phosphate whereas the plants give organic nutrients to the fungi.
3. Rhodospirillum is a gram-negative pink colour bacteria.
4. It is a free-living nitrogen-fixing bacteria.
5. It can also be used to produce biofuel as well as biological hydrogen fuel.

Explanation of incorrect options:

Option A:

Frankia is a nitrogen-fixing bacteria that can live in symbiotic association with the plant Alnus.

Option C:

Anabaena azollae is a cyanobacterium that fixes atmospheric nitrogen and lives in symbiotic association with the water fern Azolla.

Option D:

Rhizobium is a gram-negative motile rod-shaped proteobacterium that lives in symbiotic association with leguminous plants like Alfalfa.

Final answer: The incorrect pair is Rhodospirillum-Mycorrhiza.