The life cycle of a fungus includes a fruiting structure that produces spores, the spores themselves and the germination of spores into a new fungus. The exact mechanism differs between sexual and asexual reproduction.
Asexual reproduction in fungi occurs one of two ways. In the first, the mycelium, or body of the fungus, produces spores that develop into new fungi. In the second, the mycelium itself fragments, and each piece becomes a new fungus. Both of these methods of asexual reproduction result in new organisms that are genetic copies of the original and allow for populations to form quickly.
Sexual reproduction in fungi involves meiosis, just as it does in animals. Sexual reproduction for fungi begins when branching structures, called hyphae, of two compatible organisms join. This joining produces specialized structures, or fruiting bodies, that undergo meiosis, halving their chromosome numbers. The resulting haploid cells produce spores that germinate to form new fungi. As in animals, fungal sexual reproduction allows for genetic variation within species.
Both sexual and asexual forms of reproduction often require the dispersal of spores to prevent overcrowding in the immediate area. Some fungi discharge their own spores, whereas others rely on environmental forces, such as insects, to do so. The dusty cloud that emerges from a puffball is actually the fungal spores dispersing.