Question

what must skeletal muscles do to move?
a. engage their fibers slowly
b. twitch involuntarily
c. separate from the bone
d. contract and relax

Explanation:

Skeletal muscles move by contracting (shortening) and relaxing. When a muscle contracts, it pulls on the bone it is attached to, causing movement. Relaxation allows the muscle to return to its original length.

• Option A: Engaging fibers slowly is not the key mechanism for movement.
• Option B: Skeletal muscles are voluntary muscles, not involuntary twitching.
• Option C: Separating from the bone would not enable movement; muscles are attached to bones.

So, the correct answer is D as contraction and relaxation are the fundamental processes for skeletal muscle - induced movement.

Answer:

D. contract and relax