Asingle motor neuron and the population of muscle fibers that it innervates is called a(n):

Motor unit

Explanation: Motor unit is a term used to describe a single motor neuron innervating the fibers of skeletal muscles. The axon endings of this motor neuron is in contact with the muscle fibers. The fibers in the motor unit are all of the same kind, but the number can vary from muscle to muscle. Activation of the motor unit causes contraction of the muscle fibers.

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).

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