Aside from twins, another group that has been studied for genetic factors in the appearance of psychological traits and disorders are ______.

Compared to axons without myelin sheaths, what is the speed of action potentials through myelinated axons?

a) faster because ion exchange occurs along the entire axon b) slower because ion exchange occurs along the entire axon c) faster because ion exchange occurs only at the nodes of Ranvier d) slower because ion exchange occurs only at the nodes of Ranvier

Why is it inaccurate and poor scientific judgment to make conclusions based on case studies?

A. Case studies can provide little information about a disorder. B. Few patients are willing to be used as case studies. C. It is unethical. D. Conclusions based on so little data are likely to be flawed.