Trisomy 21
a. only occurs to infants of women who get pregnant at 45 years or older.
b. is caused by nondisjunction.
c. is caused by having three X chromosomes.
d. is usually lethal.
e. occurs only among non-human primates.
Question 2
Which is NOT true about recombination?
a. It is the exchange of genetic material between paired chromosomes
b. It is also called crossing over
c. It occurs during mitosis
d. Its pairing ensures each new daughter cell receives only one of each pair.
e. It occurs in gamete formation.