What does the mold biology domain cover on the AMRT exam?
It covers what fungi are and what they need: a food source, moisture and suitable temperature, plus time. From there the exam works through structure — spores, hyphae, mycelium — how fungi feed, which genera turn up on chronically wet cellulose, and what mycotoxins and MVOCs actually are.
The health side is tested at the level a technician needs: allergenic, irritant, pathogenic and toxigenic responses, and which occupants are more susceptible. You are not being asked to diagnose anyone. You are being asked to explain why a musty smell means active growth somewhere, why the count in outdoor air matters as a comparison, and why killing mold does not remove the allergen. Start with the Mold Biology & Health Effects module.
Where do candidates lose points on biology questions?
Terminology drift. Mycotoxin, MVOC and spore get used interchangeably in the field, and the exam does not allow that. A mycotoxin is a chemical produced by some fungi under some conditions; an MVOC is the gas you smell; a spore is the reproductive unit that travels. Three different things, three different implications.
Candidates also over-claim on health. A question asking what sneezing and watery eyes near mold represent has a specific answer, and "toxic mold poisoning" is not it. Keep the answer at the level of exposure response. Finally, do not skip the moisture side of biology: water activity at the material surface, not the relative humidity in the middle of the room, is what governs whether something grows.
How should you study mold biology?
Learn the growth requirements first — they explain every other answer in the domain. If you can say what removes the moisture leg of the triangle on a given job, most biology questions collapse into common sense.
Then memorize the vocabulary with the flashcards, read mold biology basics for the version written in job-site language, and use the glossary anchors above when a term will not stick. For the public-health framing that shows up in occupant conversations, the EPA's mold pages at epa.gov/mold are the source to quote rather than a manufacturer's brochure.