Question

question 16
1 part | -- of 1 point

when a skeletal muscle fiber contracts, the

width of the a band increases.

h bands and i bands get larger.

z lines move further apart.

zones of overlap get larger.

all of the answers are correct.

Explanation:

• During skeletal muscle fiber contraction:
• The A - band (which contains thick myosin filaments) does not change in width as it is a constant length.
• The H - band (a region with only thick filaments in the A - band) and I - band (a region with only thin actin filaments) decrease in size as the thin filaments slide over the thick filaments.
• The Z - lines move closer together as the sarcomere (the basic unit of muscle contraction) shortens.
• The zones of overlap (where thick and thin filaments overlap) increase as the thin filaments slide towards the center of the sarcomere.

Answer:

zones of overlap get larger.