Nondisjunction can occur at either the first or second division of meiosis.XXY individuals could arise from nondisjunction at the ________ meiotic division in the ________.
A)first; mother
B)second; mother
C)first; father
D)second; father
E)More than one of the choices could give rise to XXY individuals.

Question

Quizplus · Accepted Answer

Nondisjunction at either the first or second meiotic division in either the mother or the father can lead to the formation of XXY individuals. In the mother, nondisjunction at the first division would result in an egg with two X chromosomes, and in the father, nondisjunction at the first division would result in a sperm with both an X and a Y chromosome. Similarly, nondisjunction at the second division in either parent could also lead to gametes with an extra X chromosome, which, when fertilized, would result in an XXY individual.

Nondisjunction Can Occur at Either the First or Second Division