The somatic nervous system can alter the activities of its targets, the skeletal muscle fibers, because a) it is electrically coupled by gap junctions to the muscles. b) its signals bind to receptor proteins on the muscles. c) its signals reach the muscles via the blood.

B) its signals bind to receptor proteins on the muscles

Explanation:

Somatic nervous system is together with autonomic nervous system part of the peripheral nervous system. Its role is to control the movements of skeletal muscles which means that this nervous system is under the voluntary control (unlike autonomic which is involuntary nervous system). Somatic system consists of two types of nerves:

The axons of the efferent nerves  form a neuromuscular junction with the effector cells, muscle cells.

the correct answer is sex-linked recessive.

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