Which group of microorganisms includes yeast and molds?

The correct answer is fungi because this group encompasses a wide variety of organisms, primarily including yeast and molds. Fungi are distinct from other microorganisms in that they have a complex cellular structure and can exist as single cells (yeasts) or multicellular organisms (molds).

Yeasts are typically unicellular and are known for their role in fermentation processes, such as in baking and brewing. Molds, on the other hand, are filamentous fungi that grow in multicellular structures called mycelium and are often found in decomposing organic matter.

This classification is particularly important in various fields including food science, medicine, and environmental biology. Understanding fungi is crucial as they can have beneficial applications (like in antibiotics) as well as harmful effects (such as fungal infections in humans).

The other groups mentioned, while also important, do not include both yeasts and molds under their classification. Bacteria are prokaryotic, viruses are acellular entities requiring host cells to replicate, and protozoa are mainly single-celled eukaryotic organisms that are distinct from fungi in both structure and function.