After the peak of an action potential, what prevents sodium ions from continuing to enter the cell?
a. There is no longer a concentration gradient for sodium
b. The sodium-potassium pump greatly increases its rate of activity.
c. All the available sodium ions have already entered the cell.
d. The sodium gates in the membrane close.
d
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If you are a high-status person in a hierarchically organized group, most likely
a. you will initiate more communications than a low status person. b. you will receive few communications from equal status persons. c. you will be more dissatisfied with your position in the group. d. the communications you receive from lower status persons will be negative.
Widely abused illegal drugs such as cocaine, heroin, and amphetamines are attractive to users because
a. they stimulate the brain's "reward circuits." b. they helped our ancestors survive and reproduce. c. they suppress REM sleep. d. they slow down mental and physical activity. e. they produce hallucinations and delusions.
Craig is currently in therapy to help him stop smoking. His therapist is using learning techniques to help him modify his smoking habit and develop more desirable behaviors. Craig's therapist is using __________
a) behavior modification. b) empty chair technique. c) reflection. d) selective thinking.
Fragile-X syndrome afflicts approximately one in every ______ males
a. 1,250 c. 2,250 b. 1,750 d. 2,750