Answer to Question 1
3, 4, 5
Explanation: 3. Couples who have had a child with trisomy 21, 18, or 13 have approximately a 1 risk or their age-related risk, whichever is higher, of a future child having a chromosome abnormality.
4. Family history of neural tube defects is an indication for genetic amniocentesis.
5. If both parents carry an autosomal recessive disease, they have a 25 chance with each pregnancy that the fetus will be affected.
Answer to Question 2
C