NEET BIOLOGY

Detailed explanation-1: -Central nervous system (CNS) axons do not spontaneously regenerate after injury in adult mammals. In contrast, peripheral nervous system (PNS) axons readily regenerate, allowing recovery of function after peripheral nerve damage.

Detailed explanation-2: -The central nervous system (CNS) is the only tissue in the body that does not regenerate. Other organs may regenerate by the multiplication of intact cells but this is compensatory hyperplasia and not true regeneration.

Detailed explanation-3: -A few types of tissue are composed of cells that have left the cell cycle permanently, and are therefore unable to proliferate. These nondividing tissues (or permanent tissues) include cardiac and skeletal muscle.

Detailed explanation-4: -The chance of nerve regeneration is greater within the peripheral nervous system. This is because these neurons have a different lining, or sheath, made up of Schwann cells. The central nervous system does not have these cells. Schwann cells can help damaged nerves regenerate and restore function.

Detailed explanation-5: -The ability of muscle tissue to regenerate is limited. Fibrous connective tissue often replaces damaged muscle tissue. Nerve tissue has even less capacity to regenerate as the cell division in the nervous tissue is restricted to the early stages of development. So, the correct answer is option D.