Myofibril contractile subunits,the sarcomeres,are bounded on each end by a disc of protein called the
A)H band.
B)I band.
C)A band.
D)Z line.
E)M line.

Question

Quizplus · Accepted Answer

The Z line or Z disc is a disc of protein that divides each sarcomere from one another at its ends. It serves as the anchoring point for the thin filaments, which extend towards the center of the sarcomere, and it helps maintain its structure during muscle contraction. The other choices, such as H band, I band, A band, and M line, serve different functions within the sarcomere but are not the discs that bound the sarcomere itself.

Myofibril Contractile Subunits,the Sarcomeres,are Bounded on Each End by a Disc