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Phycomycetes is an obsolete [1] [2] [3] polyphyletic taxon for certain fungi with aseptate hyphae. [4] It is used in the Engler system. [5] Asexual reproduction takes place by zoospores (motile) or by Aplanospores (non-motile).
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and ...
Asexual reproduction process in ascomycetes also involves the budding which we clearly observe in yeast. This is termed a "blastic process". It involves the blowing out or blebbing of the hyphal tip wall. The blastic process can involve all wall layers, or there can be a new cell wall synthesized which is extruded from within the old wall.
Scientists have made some major achievements with cloning, including the asexual reproduction of sheep and cows. There is a lot of ethical debate over whether or not cloning should be used. However, cloning, or asexual propagation, [21] has been common practice in the horticultural world for hundreds of years.
Asexual reproduction can proceed by budding, fission, or spore formation and does not involve the union of gametes, which accordingly results in a much faster rate of reproduction compared to sexual reproduction, where 50% of offspring are males and unable to produce offspring themselves.
Conditions necessary for spore maturation differ among species. In asexual reproduction, the mother fungi and offspring are genetically identical. [4] Asexual reproduction is the predominant form of reproduction and dispersal in powdery mildew infections of wheat and barley species, as compared to sexual reproduction. [6]
A female produces an ovum with a full set (two sets of genes) provided solely by the mother. Thus, a male is not needed to provide sperm to fertilize the egg. This form of asexual reproduction is thought in some cases to be a serious threat to biodiversity for the subsequent lack of gene variation and potentially decreased fitness of the offspring.
However, these eukaryotes probably are not primitively asexual, but have lost their sexual reproduction, or it just was not observed yet. [27] [28] Many eukaryotes (including animals and plants) exhibit asexual reproduction, which may be facultative or obligate in the life cycle, with sexual reproduction occurring more or less frequently. [29]