Food feed
A gas signal
Apples produce ethylene, a gaseous plant hormone that helps coordinate ripening. Its effects include changes in firmness, color, starch, and flavor, but growers assess more than this single signal.
Berry
Bananas are botanical berries, while strawberries are aggregate accessory fruits. The distinction depends on how a flower becomes a fruit, not on sweetness, size or the name on a grocery label.
Legume
Peanuts are legumes, in the same plant family as peas and beans, rather than true botanical nuts. Their unusual feature is that the flowers develop above ground but the pods mature below it.