Regeneration is defined as organism's ability to regrow damaged or lost body parts. It is a type of asexual reproduction which is shown by many fully differentiated organisms. Organism such as
Hydra uses regenerative cells for reproduction in the process of budding. When
Hydra reaches maturity and is well fed, its body wall begins to form a rounded growth from the stalk of the adult. This growth is called a bud which develops in time into a miniature
Hydra. The body layers, body cavity and digestive cavity of the young Hydra are continuous with that of the parental
Hydra. The young
Hydra gets its nourishment from the parent. When the young
Hydra is sufficiently developed to take up an independent existence, the base of the new
Hydra seals off and thus allows the new individual to break off from the parent
Hydra.