Answer the following statements true (T) or false (F)

Question

1. Skeletal muscle fibers have more than one nucleus.
2. In order for something to be considered a skeleton, it must contain bone or some other hard substance.
3. You would expect to find higher myoglobin levels in oxidative muscle fibers than in glycolytic muscle fibers.
4. You would expect to find more mitochondria in glycolytic muscle fibers than in oxidative muscle fibers.

Answer 1

1. TRUE
2. FALSE
A skeleton is any structure that provides support and protection and also functions in locomotion. Skeletons are not necessarily composed of hard bone. Three types of skeletons are found in animals. In hydrostatic skeletons, found in many soft-bodied invertebrates, muscle contractions create differences in hydrostatic pressure that support the body and generate movements. In arthropods, exoskeletons are protective external structures that must be shed to accommodate growth of the animal. Endoskeletons—found in some species of sponges and all echinoderms and vertebrates—are internal structures that grow with the animal but do not protect its body surface.
3. TRUE
4. FALSE
Fibers that contain numerous mitochondria and have a high capacity for oxidative phosphorylation are classified as oxidative fibers. By contrast, glycolytic fibers have few mitochondria but possess both a high concentration of the proteins involved in glycolysis and large stores of glycogen, the storage form of glucose.