Which feature characterizes slow-twitch skeletal muscle fibers?
A) Ability to develop tension quickly
B) Large amounts of myoglobin
C) Few mitochondria
D) Higher ATPase activity than fast-twitch fibers
E) Fewer blood vessels than fast twitch-fibers in the same muscle

Question

Quizplus · Accepted Answer

Slow-twitch skeletal muscle fibers have large amounts of myoglobin, which is used for oxygen storage and is necessary for oxidative metabolism. Myoglobin gives these fibers their red color.

Answer: C
 Slow-twitch skeletal muscle fibers have relatively few mitochondria compared to fast-twitch fibers. Mitochondria are responsible for producing ATP through oxidative metabolism, which is the dominant pathway for energy production in slow-twitch fibers.

Answer: E
 Slow-twitch skeletal muscle fibers have more blood vessels than fast-twitch fibers in the same muscle. This is because these fibers rely heavily on oxidative metabolism and require a constant supply of oxygen and nutrients.

Note: None of the options provide the correct choice alone.

Which Feature Characterizes Slow-Twitch Skeletal Muscle Fibers