Fast-twitch fibers (i.e. ,type IIx)contain a relatively
A)large number of mitochondria and low ATPase activity.
B)small number of mitochondria and low ATPase activity.
C)small number of mitochondria and high ATPase activity.
D)moderate numbers of mitochondria and low ATPase activity

Question

Quizplus · Accepted Answer

Fast-twitch fibers have a small number of mitochondria and high ATPase activity, allowing for quick energy production and contraction. Type IIx fibers specifically are the fastest and most powerful of the fast-twitch fibers, so they would have even fewer mitochondria and higher ATPase activity compared to the other fast-twitch fibers (IIa).

Fast-Twitch Fibers (I.e. ,Type IIx)contain a Relatively