19 Zygotic meiosis is very common in organisms like green algae and fungi. In this type of life cycle, the organism exists for most of the cycle as a multicellular, haploid organism. This organism at some point produces gametes via mitosis, which then unite to form a diploid zygote. The zygote undergoes a meiotic division and haploid spores are the result. These spores germinate to produce a new multicellular gametophyte. Hence, the only multicellular stage is the gametophyte, and meiosis takes place in the zygote to produce spores. 2. Life Cycle Exhibiting Sporic Meiosis: Some green and brown algae, as well as the red algae and all plants exhibit life cycles with sporic meiosis. All organisms possessing this life cycle exhibit alternation of generations , where a multicellular, haploid form of the organism (the gametophyte ) alternates with a multicellular diploid form (the sporophyte ). If the two generations appear to be identical, then the organism is said to exhibit isomorphic alternation of generations. If
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This note was uploaded on 12/27/2011 for the course BSC 1020 taught by Professor Danmoon during the Fall '11 term at UNF.