Question

Study the following and pick up the incorrect statements:
I.The axolemma has more \( K^+ \) leakage channels than \( Na^+ \) leakage channels.
II.Ligand gated channels open or close in response to electrical stimuli.
III.Voltage gated channels open in response to a change in membrane potential.
IV.Speed of conduction of nerve impulse is more in non myelinated nerve fibre than the myelinated nerve fibre.

• A. I, II
• B. II, IV
• C. I, IV
• D. II, III

Hint:

Remember, myelinated fibers conduct nerve impulses faster due to saltatory conduction. Non-myelinated fibers conduct more slowly as the impulse must travel along the entire length of the fibre.

Answer 1

The Correct Option is B

Understanding the given statements
- Statement I: Correct
- The axolemma (plasma membrane of axon) has more K\textsuperscript{+} leakage channels than Na\textsuperscript{+} leakage channels, maintaining the resting membrane potential.
- Statement II: Incorrect
- Ligand-gated channels open or close in response to chemical signals (ligands like neurotransmitters), not electrical stimuli.
- Electrical signals control voltage-gated channels instead.
- Statement III: Correct
- Voltage-gated channels respond to changes in membrane potential, allowing the movement of ions across the membrane.
- Statement IV: Incorrect
- Myelinated nerve fibers conduct impulses faster than non-myelinated fibers due to saltatory conduction, where impulses jump between Nodes of Ranvier.
Examining the given options
- Option 1 (I, II) → Incorrect (I is correct).
- Option 2 (II, IV) → Correct, as both II and IV are incorrect.
- Option 3 (I, IV) → Incorrect (I is correct).
- Option 4 (II, III) → Incorrect (III is correct).
Conclusion
Since the incorrect statements are II and IV, the correct answer is Option (2): II, IV.