In a lichen, what does the fungal partner provide to the photosynthetic partner?

In a lichen, what does the fungal partner provide to the photosynthetic partner?

• A. Protects and provides water and nutrients for the algae/cyanobacteria
• B. Photosynthesizes to provide food
• C. Fixes nitrogen for the algae
• D. Degrades rocks for the algae

Answer: (A)

In a lichen, the fungus supplies a protective, moisture-rich environment and nutrients that the photosynthetic partner needs to survive in often harsh conditions. The fungal hyphae form a surrounding structure that traps water from rain and humidity, concentrates minerals, and shields the algae or cyanobacteria from desiccation and intense light. This nurturing setup is essential because the photosynthetic partner then converts light into sugars and shares those carbohydrates with the fungus, fueling the whole symbiosis. The fungal partner does not perform photosynthesis itself, which is why that option doesn’t fit. Nitrogen fixation, when it occurs, is done by some photobionts, not by the fungus, and while fungi can weather rocks, the primary role relevant to supporting the photobiont is providing water, nutrients, and protection.

In a lichen, the fungus supplies a protective, moisture-rich environment and nutrients that the photosynthetic partner needs to survive in often harsh conditions. The fungal hyphae form a surrounding structure that traps water from rain and humidity, concentrates minerals, and shields the algae or cyanobacteria from desiccation and intense light. This nurturing setup is essential because the photosynthetic partner then converts light into sugars and shares those carbohydrates with the fungus, fueling the whole symbiosis. The fungal partner does not perform photosynthesis itself, which is why that option doesn’t fit. Nitrogen fixation, when it occurs, is done by some photobionts, not by the fungus, and while fungi can weather rocks, the primary role relevant to supporting the photobiont is providing water, nutrients, and protection.