The reproductive cycle of the Fungi kingdom Kingdom Fungi comprises the fungi, such as mushrooms, molds, and yeasts, eukaryotic heterotrophs that digest food outside of their bodies. Most fungi are multicellular, but some, the yeasts, are simple unicellular organisms probably evolved from multicellular ancestors.
Fungi are present all over the world, in marine as well as terrestrial environments.
Most fungi are decomposers, breaking dead organisms down into detritus and returning inorganic nutrients to the ecosystem. As such, fungi are also extremely adaptable, and can break down many substances, including some toxic pollutants. This adaptability also accounts for the presence of fungi in many very different environments around the world. A fungal organism consists of a mass of threadlike filaments called hyphae, which combine to make up the fungal mycelium. Each hypha is composed of a chain of fungal cells, or, in some organisms, a continuous cytoplasm with many nuclei.