Fungi reproduce sexually through either cross- or self-fertilization, involving two distinct mating types designated as $+$ and $-$ types. During this process, haploid fungi form hyphae with gametes at their tips. After the cytoplasm and nuclei of these gametes fuse, the resulting diploid zygote undergoes meiosis to produce spores, which germinate to initiate a new haploid stage and form haploid mycelia.