REGENERATION IN PLANARIA:
many differentiated organismshave the ability to give rise to new individual organisms from their body parts. that is if the individual is somehow cut or broken up into many parts, many of these parts grow into new individuals .for example, simple animals like hydra, planaria can be cut into any number of pieces and each piece grows into complete organism.. this is known as regeneration .regeneration is carried out by specialised cells. from this mass number of cells,different cells undergo change to become various cell types and tissues. these changes takes place in an organised sequence referred to as development.