Which among the following is the mismatched option ?
a) Rhodospirillum - Mycorrhiza
b) Anabaena - Nitrogen fixer
c) Rhizobium - Alfalfa
d) Frankia - Alnus

a

The mismatched option among the given choices is: a) Rhodospirillum - Mycorrhiza

Rhodospirillum is a type of purple non-sulfur bacteria known for its photosynthetic capabilities. It's not typically associated with mycorrhiza. Mycorrhiza is a symbiotic association between certain fungi and plant roots. Rhizobium, Anabaena, and Frankia are all associated with specific plant symbioses:

b) Anabaena - Nitrogen fixer: Anabaena is a type of cyanobacteria that forms symbiotic associations with certain plants (like Azolla) and can fix atmospheric nitrogen.

c) Rhizobium - Alfalfa: Rhizobium is a genus of bacteria capable of forming nitrogen-fixing nodules on the roots of leguminous plants such as garden pea, Alfafa, Sweet clover, etc.

d) Frankia - Alnus: Frankia is known as a microbe that produces a nitrogen-fixing nodule on the roots of non-leguminous plants. They depict symbiotic relationships with plants belonging to the genus Alnus.

Therefore, the mismatched option is a) Rhodospirillum - Mycorrhiza.