Question

why is regeneration is not possible in all type of animals?

Answer 1

Regeneration can be defined as the natural ability of living organisms to replace worn out parts, repair or renew damaged or lost parts of the body, or to reconstitute the whole body from a small fragment during the post embryonic life of an organism. Regeneration is thus also a developmental process that involves growth, morphogenesis and differentiation.

Answer 2

Reformation is not possible in all types of animals because all animals always don't exist in thier embryonic form.

$\textbf{Regeneration}$

The ability of loving things to repair themselves or grow the damaged part is called regeneration.

Example : Hydra.