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Asexual definition biologia imagenes

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Asexual reproduction Asexual definition biologia imagenes is a type of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it does not involve the fusion of gametesand almost never changes the number of chromosomes. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many plants and fungi sometimes reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, mechanisms for lateral gene transfer such as conjugationtransformation and transduction can be likened to sexual reproduction in the sense of genetic recombination in meiosis.

It is not entirely understood why the ability to reproduce sexually is so common among them. Current hypotheses [3] suggest that asexual Asexual definition biologia imagenes may have short term benefits when rapid population growth is important or in stable environments, while sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments. Developmental constraints [4] may underlie why few animals have relinquished sexual reproduction completely in their life-cycles.

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Another constraint on switching from sexual to asexual reproduction would be Asexual definition biologia imagenes concomitant loss of meiosis and the protective recombinational repair of DNA damage afforded as one function of meiosis. An important form of fission is binary fission, where the parent organism is replaced by two daughter organisms, because it literally divides in two.

Only prokaryotes the archaea and the bacteria reproduce asexually through binary fission. Eukaryotes such as protists and unicellular fungi may reproduce in a functionally similar manner by mitosis ; most of these are also capable of sexual reproduction. Multiple fission at the cellular level occurs in many protistse.

The nucleus of the parent cell divides several times by mitosisproducing several nuclei. The cytoplasm then separates, creating multiple daughter cells. In apicomplexansmultiple Asexual definition biologia imagenes, or schizogony appears either as merogonysporogony or gametogony.

Merogony results in merozoiteswhich are multiple daughter cells, that originate within the same cell membrane, [10] [11] sporogony results in sporozoitesand gametogony results in micro gametes. Some cells split via budding for example baker's yeastresulting in a "mother" and "daughter" cell. The offspring organism is smaller than the parent. Budding is also known on a multicellular level; an animal example is the hydrawhich reproduces by budding. The buds grow into fully matured individuals which eventually break away from the parent organism.

Internal budding is a process of asexual reproduction, favoured by parasites such as Toxoplasma gondii.

It involves an unusual process in which two endodyogeny or more endopolygeny daughter cells are produced inside a mother cell, which is then consumed by the offspring prior to their separation. Also, budding external or internal is present in some worm like Taenia or Echinococci ; these worm produce cyst and then Asexual definition biologia imagenes invaginated or evaginated protoscolex with budding.

Vegetative propagation is a type of asexual reproduction found in plants where new individuals are formed without the production of seeds or spores by meiosis or syngamy. Other plants reproduce by forming bulbs or tubers for example tulip bulbs and dahlia tubers.

Some plants produce adventitious shoots and may form a clonal colonywhere all the individuals are clones, and the clones may cover a large area. Many multicellular organisms form spores during their biological life cycle in a process called sporogenesis.

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