Respuesta :
Yeasts are eukaryotic, single-celled microorganisms classified as
members of the fungus kingdom. The first yeast originated hundreds of
millions of years ago, and 1,500 species are currently identified. They
are estimated to constitute 1% of all described fungal species. Yeasts
are unicellular organisms which evolved from multicellular ancestors,
with some species having the ability to develop multicellular
characteristics by forming strings of connected budding cells known as
pseudohyphae or false hyphae. Yeast sizes vary greatly, depending on
species and environment, typically measuring 3–4 µm in diameter,
although some yeasts can grow to 40 µm in size. Most yeasts reproduce
asexually by mitosis, and many do so by the asymmetric division process
known as budding.
Yeast, any of about 1,500 species of single-celled fungi, most of which are in the phylum Ascomycota, only a few being Basidiomycota. Yeasts are found worldwide in soils and on plant surfaces and are especially abundant in sugary mediums such as flower nectar and fruits. There are hundreds of economically important varieties of ascomycete yeasts; the types commonly used in the production of bread, beer, and wine are selected strains of Saccharomyces cerevisiae. Some yeasts are mild to dangerous pathogens of humans and other animals, especially Candida albicans, Histoplasma, and Blastomyces. As fungi, yeasts are eukaryotic organisms. They typically are …(100 of 333 words)