In
biology,
regeneration is the process of renewal, restoration, and growth that makes
genomes,
cells,
organisms, and
ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every
species is capable of regeneration, from
bacteria to humans. Regeneration can either be complete where the new tissue is the same as the lost tissue, or incomplete where after the necrotic tissue comes
fibrosis. At its most elementary level, regeneration is mediated by the molecular processes of
gene regulation. Regeneration in biology, however, mainly refers to the
morphogenic processes that characterize the
phenotypic plasticity of
traits allowing 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. Regeneration is different from
reproduction. For example,
hydra perform regeneration but reproduce by the method of
budding.