Mycorrhizae are mutualistic associations between fungi and the roots of higher plants. What does the plant provide to the fungus in this association?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Energy-yielding carbohydrates
Mycorrhiza is a mutualism, so both partners gain. The fungus helps the plant absorb essential nutrients from the soil. In return, the plant, which makes food by photosynthesis, gives the fungus energy-yielding carbohydrates.
Option (1) Phosphorus absorbed from the soil — Incorrect. Phosphorus moves the other way. The fungal partner (for example Glomus) absorbs phosphorus from the soil and passes it to the plant.
Option (2) Energy-yielding carbohydrates — Correct. The plant gives the fungus carbohydrates, its source of energy.
Option (3) Mineral nutrients absorbed from the soil — Incorrect. Mineral nutrients are absorbed from the soil by the fungus for the plant. This is what the plant receives, not what it gives.
Option (4) Resistance to root-borne pathogens — Incorrect. Resistance to root-borne pathogens is another benefit the plant gets from having mycorrhiza. The plant does not give it to the fungus.
NCERT Extract:
Population Interactions – “… Similarly, the mycorrhizae are associations between fungi and the roots of higher plants. The fungi help the plant in the absorption of essential nutrients from the soil while the plant in turn provides the fungi with energy-yielding carbohydrates.”
Microbes as Biofertilisers – “… Many members of the genus Glomus form mycorrhiza. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development.”