Question 8
Turner syndrome and Klinefelter syndrome both trace back to the same kind of event. What is it?
The right answer is the one marked above.
The twenty-third pair failing to separate during meiosis. One gamete then receives both sex chromosomes and the other receives none, giving 47 chromosomes in one case and 45 in the other.
These conditions are genetic but not inherited in the sense the first skill defined — they almost always arise afresh, in the formation of a single gamete.