Question

Which statement is correct for muscle contraction?

(a) Length of H-zone decrease

(b) Length of A-band remains constant

(c) Length of I-band increases

(d) Length of two Z-line increases

Answer 1

Correct Option (b) Length of A-band remains constant
Explanation:

When Ca⁺ ions combine with troponin then in consequence muscle contraction will initiates. During contraction, the Z-lines come closer together and the sarcomere becomes shorter. The length of A-band remains constant. I-bands shortens and H-zone narrows.