A single mushroom can produce billions of spores, ensuring that it passes on its genetics for many years to come. Once the conditions become conducive to growth, these haploid spores germinate into cottony tangles of hyphae called mycelia.
The cytoplasms of the + and – type gametes fuse (plasmogamy), producing a cell with two distinct nuclei (a dikaryotic cell). Later, the nuclei fuse (karyogamy) to create a diploid zygote. Soon after fusion, meiosis takes place, resulting in four haploid nuclei. The nuclei then migrate to the sterigmata of the basidium and form four individual projections. These projections are then separated by cell walls to become spores. The dispersal of these monokaryotic spores completes the life cycle.