Axons of neurons become coated with ________, a fatty substance that provides protection and speeds the transmission of nerve impulses

When considering all of the grand and newer theories, which one of the following statements best summarizes their application and usefulness?

All of the grand and newer theories have strengths and weaknesses. No one theory is applicable across all behaviors. While the grand theories have been proven to be useful over time, the newer theories require further study before we can assess their value. Virtually all of the theories proposed so far have been useful only to provide the framework for ongoing research. Research developmentalists are finding the newer theories to be far more applicable to modern-day behaviors than the grand theories.

Which of these is the best description of REM sleep?

a) light sleep dominated by delta waves b) deep sleep dominated by alpha waves c) sleep with a low probability of dreaming d) sleep with a high probability of dreaming