What is the role of fungal symbiont in mycorrhiza?

The correct answer is Option (1) → Absorbs phosphorus from the soil and passes it to the plant

A mycorrhiza is an association between a fungus (e.g. Glomus) and the roots of a higher plant. Both gain: the plant gets minerals, and the fungus gets sugars made by the plant.

Option (1) Absorbs phosphorus from the soil and passes it to the plant — Correct. The fungal threads spread far into the soil and take up phosphorus for the plant.

Option (2) Adds organic matter to the soil — Incorrect. NCERT says this of blue-green algae (cyanobacteria), not of the mycorrhizal fungus.

Option (3) Fixes atmospheric nitrogen — Incorrect. Nitrogen is fixed by bacteria such as Rhizobium and Azotobacter and by cyanobacteria, not by fungi.

Option (4) Increases soil fertility — Incorrect. The fungus feeds the plant; NCERT credits cyanobacteria with increasing soil fertility.

NCERT Extract:
Microbes as Biofertilisers – …