Question

How does sexual reproduction occur in ascomycetes and basidiomycetes ?

Answer 1

Hint: The fungus can adapt to different surroundings thanks to sexual reproduction, which is a major source of genetic diversity. In many aspects, the mechanism of sexual reproduction in mushrooms is unique. In other eukaryotes, such as mammals, plants, and protists, nuclear division includes the disintegration and re-formation of the nuclear membrane.

Complete answer:
In fungi, sexual reproduction is divided into three stages: plasmogamy, karyogamy, and meiosis. The diploid chromosomes are separated into two daughter cells, each of which has just one set of chromosomes (a haploid state). Plasmogamy combines two compatible haploid nuclei by fusing two protoplasts (the contents of two cells). Two nuclear types are present in the same cell at this time, but the nuclei have not merged. Karyogamy causes the haploid nuclei to fuse, resulting in the development of a diploid nucleus (i.e., a nucleus containing two sets of chromosomes, one from each parent).
The zygote is the cell generated via karyogamy. In most fungi, the zygote is the only diploid cell throughout the whole life cycle. In fungi, the dikaryotic state caused by plasmogamy is a common occurrence, and it can last for several generations. Karyogamy normally occurs almost shortly after plasmogamy in the lower fungi.
Sexual reproduction in Basidiomycota takes place in specialised structures called basidia, which are found in the fruiting body. The nuclei then travel to the basidium's end, where they generate four separate projections. Cell walls separate these extensions, resulting in spores.
Ascomycota are septate fungi having filaments divided by septa, which are cellular cross-walls. Ascomycetes generate both sexual and asexual spores, known as ascospores, which are formed in sac-like structures known as asci.

Note:
Hermaphroditic mushrooms are those that bear both male and female gametangia in a single individual. Separate individuals, one male and the other female, rarely produce gametangia of opposite sexes. Dioecious species are those that reproduce in two ways. Only in the presence of an individual of the opposite sex do dioecious organisms create sex organs.