​When you look at the cord coming out of the lamp on your de…

​When you look at the cord coming out of the lamp on your desk, you will notice that there is a protective coating that surrounds and encapsulates the electricity-conducting wire inside. If you were to relate that model to the human neuron, the protective coating would refer to the

​Marcella is interested in studying the physical development…

​Marcella is interested in studying the physical development of girls between 7 and 10 years of age. It is impractical to think that she could study every such girl in the country, so instead she selects a smaller group of girls in this age range to study. The group that Marcella studies is a(n) ________, and the larger group that they represent is a(n) ________.