Question

The frequency of Down syndrome in the human population is most closely correlated with which of the following?

A. Maternal age
B. Paternal age
C. Family history of Down syndrome
D. Socioeconomic status

Answer 1

Maternal age is most closely correlated with the frequency of Down syndrome. With increasing age, women are at an increased risk of having a baby with Down syndrome due to the frequency of chromosomal nondisjunction events.

Step-by-step explanation:

Maternal age is most closely correlated with the frequency of Down syndrome in the human population. With increasing age, women are at an increased risk of having a baby with a chromosomal abnormality like Down syndrome. This is because the frequency of chromosomal nondisjunction events, which cause trisomy 21 (Down syndrome), appears to increase with age in females over 36. The age of the male parent matters less because nondisjunction is much less likely to occur in a sperm than in an egg.