Ascomycota form various symbiotic relationships. For instance, lichen is a symbiotic association between a fungus (often an Ascomycota) and an alga or cyanobacterium. Mycorrhizal associations between Ascomycota and plant roots enhance nutrient uptake for the plant while providing carbohydrates for the fungus. Parasitic forms of Ascomycota can infect plants, animals, and humans, leading to diseases that are often studied using histological methods.
