(a) What is meant by regeneration ? Name two animals which can regenerate fully from their cut body parts.
(b) Explain why, more complex multicellular organisms cannot give rise to new organisms through regeneration.

(a) Regeneration is the process in which an organism can produce new organisms from their damaged or lost body parts. Hydra and Planaria can regenerate fully from their lost body parts.

(b) In complex multicellular organisms, the specialised cells form tissues, tissues form organs and organs coordinate to form a system. Due to this high degree of specialisation, multicellular organisms cannot reproduce by regeneration.