Microbiology Practice Test: Fungi – Molds and Yeasts — Flashcards

Fungi – Molds and Yeasts topics include:  morphology, reproduction, physiology and fungi cultivation, fungi classification and special interest.

Yeasts and molds are microscopic fungi that are part of the "cleanup crew" on Earth, breaking down old and spoiled food. They are often found in damp, dark, or steamy areas, such as on fruit, berries, and the skin and stomachs of mammals. 

Here are some differences between yeasts and molds:
Cell structure: Yeasts are unicellular organisms, while molds are multicellular.
Reproduction: Yeasts reproduce by budding or fission, while molds grow by extending their filaments, called hyphae.
Appearance: Yeasts are thread-like, white or colorless, and reproduce asexually. Molds are round, come in many colors, and can reproduce sexually or asexually.
Growth: Yeasts can grow in aerobic and anaerobic conditions, while molds only grow in aerobic conditions.
pH range: Molds can only grow in a pH range of 4.0 to 4.5.
Shape: Molds are tubular branches that form a single organism, known as a colony. 

Some foodborne molds and possibly yeasts can be hazardous to human and animal health. This is because they can produce toxic metabolites called mycotoxins, which are stable compounds that aren't destroyed by food processing or home cooking.