Classified in the kingdom Fungi, with about 1,500 species currently
described: they dominate fungal diversity in the oceans. Most reproduce
asexually by budding, although a few do so by binary fission. Yeasts are
unicellular, although some species with yeast forms may become multicellular
through the formation of a string of connected budding cells known as
pseudohyphae, or false hyphae as seen in most molds.