Question

The plant life cycle involves alternation of generations. Compare and contrast the life cycles of Zygomycota, Ascomycota and Basidiomycota.

Answer 1

Ans: In the Zygomycota, mycelia produce spores via asexual reproduction. These spores get to germinate and went for sexual reproduction give rise to zygosporangium. Plasmogamy and karyogamy processes occur that ultimately form a diploid zygote structure. Further meiosis results in a sporangium and each sporangium then continue its life cycle with spore formation.

In the Ascomycota, conidiospores germinate into mycelium. The male sexual organ is called antheridium and female is known as ascogonium in mycelia. Sexual reproduction takes place and for ascocarp and further to ascocarp. Zygote formation is followed by the meiosis which forms four haploid nuclei. Now, via mitosis and cell division, 8 ascospores are generated. Each will disperse and germinated to a new ascomycete.

Basidiomycetes follow only sexual reproduction in which spores are germinated to form mycelia. Further plasmogamy and mitosis occur which form basidiocarp. Karyogamy results in the formation of four basidium and then each basidium will modified into basidiospores and they disperse in the environment for the another germination cycle.