n.
Reproductive cell capable of developing into a new individual without fusing with another reproductive cell.
Spores thus differ from gametes, which must fuse in pairs in order to create a new individual. Spores are agents of nonsexual reproduction; gametes are agents of sexual reproduction. Spores are produced by bacteria , fungi (see fungus ), and green plants. Bacterial spores serve largely as a resting, or dormant, stage in the life cycle, preserving the bacterium through periods of unfavorable conditions. Many bacterial spores are highly durable and can germinate even after years of dormancy. Fungal spores serve a function similar to that of seeds in plants; they germinate and grow into new individuals under suitable conditions of moisture, temperature, and food availability. Among green plants (all of which have a life cycle characterized by alternation of generations ), spores are the reproductive agents of the nonsexual generation ( sporophyte ), giving rise to the sexual generation ( gametophyte ).