What has research on twins revealed concerning a possible genetic etiology for autistic disorder?
a. High MZ concordance rates suggest a strong role for genetic factors.
b. Similar concordance rates for MZ and DZ twins point to the significant role of the environment.
c. Concordance rates have been low and inconsistent, suggesting little, if any, role for genetic factors.
d. Analysis of the concordance rates suggests that a predisposition to dementia is the primary etiological factor.
Answer: a.
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A. There is no impact. B. Action potentials cannot occur because the membrane cannot fully depolarize. C. Action potentials cannot occur because the membrane remains hyperpolarized. D. The nerve cell dies.
According to Masters and Johnson, during the plateau phase of the human sexual response cycle, sexual arousal continues to increase, but at a slower rate than in the previous phase
Indicate whether the statement is true or false
Based on the study by Shariff and Norenzayan (2007) presented in your text, if you pass by several churches, then a block or so later a homeless person asks you for change, how are you likely to behave?
a. You would probably take the person to the churches you passed to get help. b. You would be very unlikely to give the person money. c. You would be more likely to give the person money. d. Passing by churches would not prime you to give more money, but passing by banks might.
Which statement about the human immunodeficiency virus (HIV) is true?
A. There are currently no effective drug therapies to reduce the chance of prenatal virus transmission. B. In developing countries, more than half of all new HIV infections affect women. C. About 30 percent of new HIV infections occur in developing countries. D. Untreated HIV-infected expectant mothers pass the virus to their fetus approximately 30 percent of the time.