AIIMS 2012 Biology Myelination and Nerve Impulse Conduction Assertion Reason Question

The assertion states that the myelin sheath insulates the nerve fiber and prevents its depolarization. This is true because the myelin sheath acts as an insulator, allowing for the rapid conduction of nerve impulses through saltatory conduction, where the impulse jumps from one node of Ranvier to another. The reason claims that nerve impulses are conducted more rapidly in non-myelinated nerve fibers than in myelinated ones, which is false. In fact, myelinated fibers conduct impulses faster due to the presence of the myelin sheath. Therefore, while the assertion is true, the reason is false, making option B the correct choice. Other options are incorrect because: A) Both statements cannot be true; C) The assertion is true but the reason is false; D) Both statements cannot be false as the assertion is true.