Which of the following best defines "fungi"?

The definition of "fungi" is best captured by the description of microscopic plant parasites such as mold, mildew, or yeast. Fungi are a distinct group of organisms that belong to their own kingdom, separate from plants, animals, and bacteria. They can be unicellular, like yeast, or multicellular, such as molds and mushrooms. Fungi play diverse roles in the ecosystem, including the decomposition of organic matter and forming symbiotic relationships with plants (mycorrhizae).

This answer aligns well with the characteristics of fungi, which are not classified as bacteria, flowering plants, or insects. The other options do not accurately represent the fundamental nature of fungi or their ecological role. By understanding this definition, one appreciates the significant impact fungi can have on turf management, particularly in relation to plant health and diseases affecting cool-season grasses.