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What is regeneration? Give examples of organisms that reproduce by regeneration. |
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Answer» Thanks for your answer Prateek?✌ That is my answer ?✌ In\xa0biology,\xa0regeneration\xa0is the process of renewal, restoration, and tissue growth that makes\xa0genomes,\xa0cells,\xa0organisms, and\xa0ecosystems\xa0resilient\xa0to natural fluctuations or events that cause disturbance or damage.[1]\xa0Every\xa0species\xa0is capable of regeneration, from\xa0bacteria\xa0to humans.[2][3]\xa0Regeneration can either be complete[4]\xa0where the new tissue is the same as the lost tissue,[4]\xa0or incomplete[5]\xa0where after the necrotic tissue comes\xa0fibrosis.[5]At its most elementary level, regeneration is mediated by the molecular processes of\xa0gene regulation\xa0and involves the cellular processes of\xa0cell proliferation,\xa0morphogenesis\xa0and\xa0cell differentiation.[6][7]\xa0Regeneration in biology, however, mainly refers to the\xa0morphogenic\xa0processes that characterize the\xa0phenotypic plasticity\xa0of\xa0traits\xa0allowing multi-cellular organisms to repair and maintain the integrity of their physiological and morphological states. Above the genetic level, regeneration is fundamentally regulated by asexual cellular processes.[8]\xa0Regeneration is different from reproduction. For example,\xa0hydra\xa0perform regeneration but reproduce by the method of\xa0budding.The hydra and the\xa0planarian\xa0flatworm have long served as model organisms for their highly\xa0adaptive\xa0regenerative capabilities.[9]\xa0Once wounded, their cells become activated and restore the organs back to their pre-existing state.[10]\xa0The\xa0Caudata\xa0("urodeles";\xa0salamanders\xa0and\xa0newts), an\xa0order\xa0of tailed\xa0amphibians, is possibly the most adept\xa0vertebrate\xa0group at regeneration, given their capability of regenerating limbs, tails, jaws, eyes and a variety of internal structures.[2]\xa0The regeneration of organs is a common and widespread adaptive capability among\xa0metazoan\xa0creatures.[9]\xa0In a related context, some animals are able to reproduce\xa0asexually\xa0through\xa0fragmentation, budding, or\xa0fission.[8]\xa0A planarian parent, for example, will constrict, split in the middle, and each half generates a new end to form two\xa0clones\xa0of the original.[11]Echinoderms\xa0(such as the sea star), crayfish, many reptiles, and amphibians exhibit remarkable examples of tissue regeneration. The case of\xa0autotomy, for example, serves as a defensive function as the animal detaches a limb or tail to avoid capture. After the limb or tail has been autotomized, cells move into action and the tissues will regenerate.[12][13][14]\xa0In some cases a shed limb can itself regenerate a new individual.[15]\xa0Limited regeneration of limbs occurs in most fishes and salamanders, and tail regeneration takes place in larval frogs and toads (but not adults). The whole limb of a salamander or a triton will grow again and again after amputation. In reptiles, chelonians, crocodilians and snakes are unable to regenerate lost parts, but many (not all) kinds of lizards, geckos and iguanas possess regeneration capacity in a high degree. Usually, it involves dropping a section of their tail and regenerating it as part of a defense mechanism. While escaping a predator, if the predator catches the tail, it will disconnect Thanks for your answer? ✌ REGENERATION\xa0: When the simple animals like Hydra ,Planaria develop a new individual from their broken older part it is as regeneration. It is carried out by specialised cells which divide and differentiate to form the complete individual. These cells multiply and from this mass of cells other parts are generated. Regeneration follows an organised sequence referred to as DEVELOPMENT. |
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