CBSE Class 10 Answered

i) When a hydra is bisected anywhere in the upper 7/8ths of the body column, the upper half will regenerate a foot at its basal end, and the lower half will regenerate a head at its apical end; each half generates the organ that it is missing. The regeneration is precise, the head and foot are always formed specifically at the apical and basal ends, respectively. The most dramatic form of regeneration in hydra is the ability to form complete animals from aggregates of cells.

ii) Growing back of tail of lizard after it has been intentionally cut off is another example of regeneration.