Which of the following descriptions best represents the appearance of the sarcomere during peak contraction?
A) The H zone is eliminated, and the I bands are very thin.
B) The width of the A band is slightly less than the width of the I band.
C) The H zone is equivalent to one-third of the length of the A band.
D) The I bands and A bands are of equal widths.

Question

Quizplus · Accepted Answer

During peak contraction of a sarcomere, the actin filaments slide closer together, causing the H zone (the region not overlapped by actin) to disappear and the I bands (light bands, which are regions with only actin filaments) to become very thin. The A band (the length of the myosin filament) remains constant in width.

Which of the Following Descriptions Best Represents the Appearance of the Sarcomere