Fungi are heterotrophic organisms that secrete enzymes to digest food outside their bodies, with most being multicellular and made of branching filaments called mycelium. They reproduce both asexually through spores and sexually depending on the species. There are five major taxonomic groups of fungi - Zygomycota, Oomycota, Ascomycota, Basidiomycota, and Deuteromycota - classified based on their sexual reproductive structures and life cycles. Fungi play important ecological roles through symbiotic relationships with plants and other organisms.
