A Woman Has a Condition Where All of Her Gametes

Multiple Choice

A woman has a condition where all of her gametes undergo nondisjunction of chromosome 21 in meiosis I, but meiosis II proceeds normally. She mates with a man who produces all normal gametes. What is the probability that the fertilized egg will develop into a child with Down syndrome? Assume that all gametes and zygotes are viable.

A) 1/8
B) 1/4
C) 1/3
D) 1/2
E) 0