In terms of cellular structure, how are yeasts primarily characterized?

Yeasts are primarily characterized as single-celled organisms. They belong to the fungi kingdom and are most commonly known for their unicellular structure, although some species may form multicellular structures under certain conditions, such as when they undergo budding or pseudohyphal growth. This single-celled nature is crucial for their roles in fermentation and in various industrial applications, such as baking and brewing.

The distinction between yeasts and other forms of fungi, such as molds or filamentous fungi, lies in their unicellular organization. Furthermore, yeasts are not photosynthetic; they obtain their energy through fermentation and the respiration of organic materials. Understanding this fundamental characteristic is essential for anyone studying mycology or infection control, as it influences how yeasts are treated and managed in clinical settings.