All or None Law

Q.

Assertion [A]: All muscles follow “all or none” principle.

Reason [R]: All muscles fibers contract either fully or do not contract at all depending upon the threshold stimulus availability.

1. Assertion [A] is True and Reason [R] is False.

2. Assertion [A] is True and Reason [R] is True and is a correct explanation to [A]

3. Assertion [A] is True and Reason [R] is True but is not a correct explanation to [A]

4. Reason [R] is True and Assertion [A] is False.

Q. Which statement is correct for muscle contraction?

1. Length of H-zone increases.
2. Length of two Z-line increases.
3. Length of A-band remains constant.
4. Length of I-band increases.