Question

explain with help of labelled diagram the development that take place in each of the body parts of a planaria where body is cut into 3 pieces .none this process and give an example of an organism in which a similar process can be observed

Answer 1

This process is called regeneration.  And example is a hydra. When Planaria is cut down into three pieces each piece grown into a separate individual. (For diagram see ncert book class 10 page no.131, fig no.8.3

Answer 2

ANSWER :

The process which occurs in Planaria where the cut parts of body develops into new ones again is called regeneration.

In this process, when the Planaria reaches a suitable developmental stage, then its body gets cut into three parts. Each parts then again develops into new complete Planaria again. This is the way of their reproduction.

This process of regeneration method can also be seen in Hydra.