Rejuvenation (biology)

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In biology, rejuvenation is the term used to describe the renewal or reproduction of a living being without prior sexual reproduction . A distinction is made between:

  • The rejuvenation through development of buds , shoots (young shoots ), stems , vines , etc., stay connected with the mother Stock (as in New green of two- and perennials , the more rungs of the floor coral etc.) or also new (as Cuttings ) can take root. So z. B. the blackberry tendrils bend downwards, penetrate the ground with the tip and take root there ; Likewise, the non-flowering central branch of the three-part stem of the Männertreu ( Veronica chamaedrys ) bends to the ground in autumn and creates a new plant by taking root. In many tropical plants, e.g. B. in the case of the holy fig tree (Ficus religiosa) germinating on trees , the trunk tapers through vertically descending aerial roots , which grow into as many trunks and columnar supports of the widely spreading canopy. In other cases, the bones ( spores , tubers , onions ) become detached from the mother plant and take root independently in the soil, e.g. B. in celandine ( Ranunculus ficaria ).
  • The rejuvenation by self-division with subsequent or already started sprouting is found especially in lower plants and animals, e.g. B. in the types of freshwater polyps (hydra), which form plant-like buds that detach and live independently, with hydroid polyps from which medusae sprout, with annelid worms , namely Naiden , which elongate by sprouting and then disintegrate into two or more individuals , with starfish and other echinoderms , which divide independently into several pieces and then complement each other through new shoots to form just as many complete individuals.