BIOSC-101 Lecture Notes - Lecture 23: Dikaryon, Pezizaceae, Ascocarp
Document Summary
Plasmogamy is the fusion of the cytoplasm of two parent cells. Karyogamy is the fusion of the nuclei. In most fungi, the nuclei of two fused hyphae do not fuse immediately but coexist in the cytoplasm. Dikaryotic- a fungal hypha that has two nuclei. If the nuclei are from genetically different individuals, it is called a heterokaryon. If the nuclei are genetically similar, then the hypha is said to be a homokaryon. Describe the generalized life cycle of a fungus and the life cycles of zygomycetes, ascomycetes and basiciomycetes. Mycelia have various mating types (+ and -) Neighboring mycelia of different mating types form hyphal extensions called gametangia each walled off around several haploid nuclei by a septum. A heterokaryotic zygosporangium forms containing multiple haploid nuclei from the two parents. This cell develops a rough thick walled coating that can resist dry environments and other harsh conditions for months. When conditions are right, karyogamy occurs followed by meiosis.