Question

You are genetic counselor meeting with a male client who has a chronic condition where all his gametes undergo nondisjunction of the sex chromosomes in meiosis I but meiosis II proceeds normally. He mates with a woman who has been shown to produces all normal gametes. The man is asking you to determine the probability that a fertilized egg from this union will develop into a child with Turner syndrome (XO)? Assume thot off gometes and zygotes ore vioble. Show your work justifying your answer. Turn in work after finishing Exam, but indicate your calculated probability below.

Answer 1

If homologous chromosomes fail to separate during meiosis I, the result is two gametes that lack that chromosome and two gametes with two copies of the chromosome. That is,   homologous chromosomes fail to separate during meiosis I, the result is two gametes that lack that chromosome and two gametes with two copies of the chromosome.

Probability 50 percentage of zygotes will have Turner syndrome