Answer to Question 1
1
1. Correct. If the parents-to-be are older and have taken fertility drugs, they would be very interested in this information.
2. Incorrect. Siamese twins are monozygotic, from one fertilized ova, in which division oc-curred very late.
3. Incorrect. Identical twins show no racial or ethnic preference; fraternal twins are more common among African-American women.
4. Incorrect. Fraternal twins can be different sexes or the same. Identical twins are the same sex.
Answer to Question 2
1
1. Correct. Three or more cups a day need to be consumed for a slight risk of a slight decrease in birth rate. Alcohol, cigarette smoke, and emotional distress have potentially much greater nega-tive effects on the health of the fetus (and the mother).
2, 3, 4. Incorrect. Three or more cups a day need to be consumed for a slight risk of a slight de-crease in birth rate. Alcohol, cigarette smoke, and emotional distress have potentially much greater negative effects on the health of the fetus (and the mother).