Question

Which of the following statement(s) is (are) true about skeletal muscles?

They constitute about 60% of a person's total body weight.

They position and move the skeleton.

The insertion of the muscle is more distal or mobile than the origin.

They are often paired into antagonistic muscle groups called flexors and extensors.

Answer 1

The statement that is true about skeletal muscles is: D. They are often paired into antagonistic muscle groups called flexors and extensors.

Step-by-step explanation:

Skeletal muscles are responsible for the movement and positioning of the skeleton. They work in pairs, with one muscle contracting (the agonist or prime mover) and its antagonist muscle relaxing, allowing for coordinated movement. Flexors are muscles that decrease the angle at a joint, while extensors increase the angle at a joint.

For example, in the arm, the biceps muscle is the flexor that closes the limb, while the triceps muscle is the extensor that opens the limb. This arrangement is typical of skeletal muscles, bones, and joints in humans and other vertebrates. Therefore the correct answer is D. They are often paired into antagonistic muscle groups called flexors and extensors.