Disjunction of the 21st chromosome that can lead to Down syndrome has been found to be related in most cases to
A) paternal age.
B) maternal age.
C) multiple codon repeats on the X chromosome.
D) the inability to metabolize phenylalanine.

Question

Quizplus · Accepted Answer

Disjunction of the 21st chromosome leading to Down syndrome is most commonly related to maternal age, as the risk of having a child with Down syndrome increases as a woman gets older.

Disjunction of the 21st Chromosome That Can Lead to Down