Define dizygotic twins. Summarize the genetic and environmental factors that increase the chances of giving birth to them
What will be an ideal response?
Answer: Dizygotic, or fraternal, twins are the most common type of multiple offspring. Fraternal twins result from the release and fertilization of two ova. Genetically, they are no more alike than ordinary siblings. Older maternal age, fertility drugs, and in vitro fertilization are major causes of the dramatic rise in fraternal twinning and other multiple births in industrialized nations over the past several decades. Currently, fraternal twins account for 1 in about every 33 births in the United States. Fraternal twinning occurs in 6 to 9 per 1,000 births among Asians and Hispanics, 9 to 12 per 1,000 births among white Europeans, and 11 to 18 or more per 1,000 births among black Africans. Dizygotic twinning occurs more often among women whose mothers and sisters gave birth to fraternal twins, suggesting a hereditary influence through the female line. Incidence of fraternal twinning rises with maternal age, peaking between 35 and 39 years, and then rapidly falls. It is more likely with each additional birth and with fertility hormones. Fraternal twinning occurs less often among women with poor diets and more often among women who are tall and overweight or of normal weight as opposed to slight body build.
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Having a general feeling that things will be okay and problems will eventually work out is known as
a. internal control b. optimism c. learned helplessness d. hardiness
Creating training programs and reward systems for groups can be
a. a valuable investment. b. worth a try, but their effectiveness is not yet clearly established. c. a total waste of time. d. helpful for virtual teams, but not face-to-face teams.
Which of the following questions exemplifies how you might critically analyze your own opinions after each section of the text?
A. asking yourself how you would test your own hypothesis B. answering survey questions that experiment participants answered C. determining how your scores on a self-report scale are different from other's in your class D. exploring ideas in new and open-minded ways
Which of the following is a real world example of using positive reinforcement to change people's behaviors so that they would increase their conservation efforts?
a. providing information regarding the number of gallons of water consumed that week b. providing rebates for buying energy-efficient appliances or cars c. placing an energy tax on gasoline d. none of these