Final answer:
In a mycorrhizal symbiosis, the fungal partner receives carbohydrates from the host plant, which are essential for the fungus's metabolism. This relationship allows the fungus to tap into a steady supply of carbon and facilitates the breakdown and uptake of soil nutrients.
Step-by-step explanation:
In a mycorrhizal symbiosis, the fungal partner receives carbohydrates such as glucose, which are products of the host plant's photosynthesis. These carbohydrates are essential to fuel the metabolism of the fungus. In return, the fungal mycelia, with their extensive network of hyphae, improve the plant's water and mineral absorption by increasing the root's surface area and accessing soil nutrients beyond the reach of the plant's own roots.
The mycorrhizae also benefit the fungi by enabling them to access up to 20 percent of the total carbon derived from the host plant. Additionally, the fungi produce enzymes that help release tightly bound soil nutrients, such as phosphate, zinc, and copper, which are transferred to the plant, facilitating the fungus's survival in various environments and providing it with a significant evolutionary advantage.