Which of the following pairs is mismatched? a) Glomus - Mycorrhiza b)…

The correct answer is Option (4) → None of these

Biofertilisers are organisms that enrich the nutrient quality of the soil. Check each pair against the book:

a) Glomus - Mycorrhiza — True. Many members of the genus Glomus form mycorrhiza; the fungus absorbs phosphorus from the soil and passes it to the plant.

b) Cyanobacteria - Important biofertiliser in paddy field — True. Cyanobacteria such as Anabaena and Nostoc fix atmospheric nitrogen and serve as an important biofertiliser in paddy fields.

c) Rhizobium - Symbiotic association with roots of leguminous plants — True. Rhizobium forms root nodules on leguminous plants and fixes nitrogen there.

d) Azospirillum - Free-living nitrogen-fixing bacteria — True. Azospirillum and Azotobacter fix nitrogen while free-living in the soil.

All four pairs are correctly matched, so no pair is mismatched.

NCERT Extract:
Microbes as Biofertilisers – “… You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient. Other bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter), thus enriching the nitrogen content of the soil. Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza.”
Microbes as Biofertilisers – “… In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter to the soil and increase its fertility.”