Question

(a) Explain the process of regeneration in Planaria.
                 (b) How is regeneration different from reproduction?

Answer 1

Hint: The dynamic body architecture of planaria facilitates surprising regenerative capacities, including the regeneration of complete and perfectly proportioned animals from tiny tissue remnants. Each portion of the body of planaria can be regenerated.

Complete answer:
Reproduction allows for the species' continuity, down the generations. It consists of two types: asexual and sexual reproduction, based on whether one or two individuals are involved in the reproductive process.
Many completely developed species have the capacity to create new individual species from their body parts. That is, whether the individual is actually split or broken apart into several sections, all of these parts will become different individuals. Planarians are free-living Platyhelminthes that can regenerate any part of the body, including the brain. Planaria can be sliced into any number of pieces and each piece can become a complete organism. This is known as regeneration.

Regeneration is achieved by specialised cells. These cells divide to create a huge number of cells. As a part of this mass of cells, various cells undergo modifications to form different types of cells and tissues. These modifications take place in an ordered sequence referred to as development. However, regeneration is not the same as reproduction, because most species will not usually rely on being cut to reproduce. Regeneration requires the species to be broken up or cut in order to give rise to new individuals.

Note: Some species of planaria may use regeneration to replicate without engaging in sexual activity. These asexual planaria divide their bodies in two and develop into a new planaria from each half. Some species can reproduce through asexual as well as sexual means.