Final answer:
The false statement is that C. red fibers have fewer mitochondria than white, when in fact they have more, which enables them to sustain long-duration, low-intensity activities.
Step-by-step explanation:
The question relates to the properties of muscle fiber types. Statement C, that 'red fibers have fewer mitochondria than white,' is not true. This statement is a common misconception about muscle fibers. Red fibers, also known as slow-twitch or oxidative fibers, are indeed packed with a substantial number of mitochondria which are necessary for aerobic metabolism. These mitochondria help produce ATP, which allows the muscles to contract for extended periods without fatiguing. Red fibers, containing the pigment myoglobin and a dense network of capillaries, are adapted for long-duration, low-intensity activities like distance running, due to their high oxidative capacity. Moreover, red fibers do fatigue more slowly compared to white fibers, due to the large amount of ATP they can generate over time.
On the other hand, white fibers, also known as fast-twitch muscle fibers, contract more quickly and fatigue faster than red fibers. They have lower levels of myoglobin and fewer mitochondria.