Bobby Pryor, age 8, of Des Moines, Iowa, for his question:

WHAT IS MOLD?

Mold is a tiny, simple plant that belongs to the fungi group. It is related to mushrooms and mildews. It has no chlorophyll, or green coloring matter, and therefore cannot manufacture its own food. It must live on food made by other plants, decaying matter or animals.

Molds develop from particles called spores. When a spore settles on damp food, such as bread, it swells and begins to grow, producing tiny threads.

Moldy food generally should be thrown away. But certain cheeses, such as Roquerfort, owe their flavor to a mold which grows in them and ripens them.

Molds also are useful because they help to break up dead organisms and waste matter and fertilize the soil. One mold produces the drug penicillin.