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The ancestral sexual system in bryophytes is unknown but it has been suggested monoicy and dioicy evolved several times. [11] It has also been suggested that dioicy is a plesiomorphic character for bryophytes. [4]: 71 In order for dioicy to evolve from monoicy it needs two mutations, a male sterility mutation and a female sterility mutation. [11]
In the bryophytes (liverworts, mosses, and hornworts), the sexual gametophyte is the dominant generation. In ferns and seed plants (including cycads , conifers , flowering plants , etc.) the sporophyte is the dominant generation; the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small.
Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. [6] [7] Sexual reproduction also occurs in some unicellular eukaryotes. [2] [8] Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such as bacteria and archaea.
Bryophytes (/ ˈ b r aɪ. ə ˌ f aɪ t s /) [2] are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses (Bryophyta sensu lato). [3]
Bryophytes are typically small plants that grow in moist locations and like ferns, have motile sperm which swim to the ovule using flagella and therefore need water to facilitate sexual reproduction. Bryophytes show considerable variation in their reproductive structures, and a basic outline is as follows: Haploid gametes are produced in ...
Bryophytes retain sexual reproduction despite the fact that the haploid stage does not benefit from heterosis. This may be an indication that the sexual reproduction has advantages other than heterosis, such as genetic recombination between members of the species, allowing the expression of a wider range of traits and thus making the population ...
The ancestral sexual system in bryophytes is unknown but it has been suggested monoicy and dioicy evolved several times. [ 13 ] In the liverwort genus Radula it was found that monoicy was a recent evolutionary acquisition connected to epiphytism , arising 6 times.
a sexual system for plants when female, hermaphrodite, and gynomonoecious plants coexist in the same population. [25]: 360 Monoicy: one of the main sexual systems in bryophytes. [18] In monoicy male and female sex organs are present in the same gametophyte. [19] Monoecy: a sexual system in which male and female flowers are present on the same ...