Their basic body plan constitutes a mass of netlike filaments called hyphae. The entire mass of hyphae is called the mycelium. Most fungal hyphae are divided into cells by cross walls called septa.
Reproduction is accomplished by the release of sexual or asexual spores.
For many species of fungi sexual reproduction is a contingency used when environmental conditions are difficult. Under favorable conditions asexual spores are produced by the millions and dispersed over a large area. Haploid conditions occur in the adult bodies of most fungi. Conjugation occurs in many fungal species. They contain a cell wall containing the material chitin.