In a mycorrhizal relationship, which statement about the fungi is true?

• A. Fungi fix carbon and provide energy to the tree
• B. Fungi absorb water and essential mineral elements while receiving nourishment from the roots
• C. Fungi perform photosynthesis to supply sugars
• D. Fungi take nutrients away from roots, harming the tree

Answer: (B)

In a mycorrhizal relationship, the key idea is mutualistic nutrient exchange: the fungus expands the tree’s ability to absorb water and minerals through its network of hyphae, while the plant feeds the fungus with sugars produced by photosynthesis. This partnership lets the tree take up essential elements like phosphorus more efficiently, especially from soils where nutrients are limited. The statement that best fits this relationship is that fungi absorb water and essential mineral elements while receiving nourishment from the roots. They are not doing photosynthesis themselves and do not fix carbon; instead, they rely on the plant for carbon, and they pass minerals and water to the plant in return.