There exists a close association between the alga and the fungus within a lichen. The fungus

Explanation

In a lichen, the association between the alga and the fungus is a mutualistic one, where both partners benefit: The fungus provides protection, anchorage, and absorption for the algae: The fungal partner forms a protective structure around the algal cells, which helps shield them from harsh environmental conditions and provides a stable substrate to grow on. The fungal partner also aids in the absorption of water and nutrients from the environment. The alga provides food for the fungus: The algal partner, through photosynthesis, produces organic compounds (such as sugars) using sunlight and carbon dioxide. These compounds serve as a source of nutrition for the fungal partner. The association typically does not involve nitrogen fixation: Nitrogen fixation is not a primary role of the fungus in the lichen symbiosis. The association does not involve the release of oxygen: While photosynthesis by the algal partner generates oxygen, the primary benefit to the fungus is the food produced by the alga. So, the correct statement is that the fungus provides protection, anchorage, and absorption for the algae, and the algae provide food for the fungus.