Acouple has a son with xyy syndrome, a condition in which an extra copy of the y chromosome is present. this condition also results from nondisjunction. during which meiotic division, and in which parent, could nondisjunction have occurred to produce a child with this condition? select all that apply. a. meiosis i in the mother b. meiosis ii in the mother c. meiosis i in the father d. meiosis ii in the father

d. Meiosis II in the father

Explanation:

Since the son has two extra Y chromosomes, the nondisjunction would have occurred in father because females do not have Y chromosome. Before Meiosis DNA replication occurs during which the homologous chromosomes are replicated. During Meiosis I crossing over occurs and homologous chromosomes separate from each other. During Meiosis II sister chromatids of a chromosome separate and move into individual daughter cells.

Here, during Meiosis II the sister chromatids of Y chromosome did not separate from each other (nondisjunction). They collectively moved to one daughter cell. As a result one daughter cell had two Y chromosomes and other daughter cell had none. When the daughter cell containing two Y chromosomes combined with the daughter cell containing one X chromosome from mother, XYY individual was born.