When a sarcomere contracts and thin filaments move over thick filaments you would expect to see__________ .
A) the H zone to appear wider
B) the A band to appear darker
C) the I bands to appear smaller
D) the I bands to appear wider

Question

Quizplus · Accepted Answer

During sarcomere contraction, the thin filaments move towards the center of the sarcomere, causing the Z discs to move closer together. This results in the I bands appearing smaller as the distance between the Z discs decreases. The H zone becomes narrower as the thin filaments move over the thick filaments, and the A band remains the same width but appears darker due to the overlap of the thin and thick filaments. Therefore, the best choice is C, as the I bands would appear smaller.

When a Sarcomere Contracts and Thin Filaments Move Over Thick