A small, usually single-celled asexual or sexual reproductive body that is highly resistant to desiccation and heat and is capable of growing into a new organism, produced especially by certain bacteria, fungi, algae, and nonflowering plants.
A dormant, nonreproductive body formed by certain bacteria in response to adverse environmental conditions.
A reproductive cell or group of cells, produced by some plants, that is capable of developing into an adult plant without combining with another reproductive cell. Plants also produce sperm cells. The spores of nonflowering plants are analogous to the seeds of flowering plants. (See asexual reproduction; compare sexual reproduction.) Fungi and algae typically reproduce by means of spores that are carried by the wind or some other agency to a new location for growth.