If you compare electron micrographs of a relaxed skeletal muscle fiber and a fully contracted muscle fiber, which would you see only in the relaxed fiber? a. Z discs b. Sarcomeres c. I bands d. A...

If you compare electron micrographs of a relaxed skeletal muscle fiber and a fully contracted muscle fiber, which would you see only in the relaxed fiber?

a. Z discs

b. Sarcomeres

c. I bands

d. A bands

e. H zones

After ACh attaches to its receptors at the neuromuscular junction, what is the next step?

a. Sodium channels open.

b. Calcium binds to regulatory proteins on the thin filaments.

c. Cross bridges attach.

d. ATP is hydrolyzed.