Coleochaete vegetative cells are haploid. Zoospores from the vegetative cells reproduce the plant asexually, as can fragmentation of the filaments. Cysts, the product of gamete fusion, are diploid. At excystment, meiosis occurs, yielding 8-32 haploid zoospores that germinate to form haploid vegetative filaments. It is presumed that the land plant progenitor had this type of life history. Insertion of mitotic divisions between the events of gamete fusion and meiosis, it is thought, led to the development of the land plant sporophyte.
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