Mold is a fuzzy fungus that grows on damp food. Tiny spores (seed-like particles) float through the air and land on surfaces like bread. When you add water and seal bread in a warm spot, those spores find the right conditions and grow into visible fuzzy patches within days.

Mold is a type of fungus that grows as fuzzy patches on damp surfaces, and temperature controls how quickly it spreads. In one experiment, bread samples receive water and brown sugar, then sit at three temperatures. The hypothesis is that warmer temperatures will cause the fungi to grow faster.

Seal a piece of bread on a damp paper towel inside a warm plastic bag, and fuzzy colonies can start to appear in as little as three days. One common mold called Rhizopus can cover an entire slice in just two days. Each day you check for new colonies and record their color and size.

Blue mold (Penicillium) and gray mold (Botrytis cinerea) are two common fungi that attack harvested pears, and fruit growers are searching for alternatives to chemical fungicides. In this experiment, you treat forty red D'Anjou pears across four groups — chlorine solution, zinc oxide solution, vegetable oil, and a plain water control. After fourteen days at room temperature, you rate each pear on a visual mold scale from 1 to 10. Comparing average ratings across the four groups reveals which treatment best protects pears after harvest.

Mold is a fuzzy fungus that loves damp, dark places. A slice of bread dampened with water drops and left in a dark spot molds fastest. A slice stored in a refrigerator holds out the longest. This shows that mold needs moisture and warmth to grow on surfaces.