Aphenotypically normal couple has a colorblind klinefelter son (xxy). in which parent and at what meiotic stage must the non-disjunction event have occurred? a. meiosis i of mother b. meiosis i of father c. meiosis ii of father d. meiosis ii of mother e. meiosis i or ii of mother f. meiosis i or ii of father

Answer;

D. Meiosis ii of mother

Explanation;

-The non-disjunction occurs in the meiosis II of the mother. This non-disjunction occurs when the two sister chromatids X and X fails to separate during meiosis II and produces an egg having two X chromosomes.

-Klinefelter syndrome is a condition that occurs in males when they have an extra X chromosome. The syndrome is not inherited, but usually occurs as a random event during the formation of reproductive cells (eggs and sperm) that results in the presence of one extra copy of the X chromosome in each cell (47,XXY).

interphase   is the cell cycle stage in which the cell acquires nutrients, creates and uses proteins and other molecules and starts the process of cell division by replicating the dna. it is the longest stage in the eukaryote cell cycle.

the following   can go wrong during interphase:   a base pair could be mismatched during the duplication process causing a mutation.   correct answer: c

explanation:

the fossil record provides evidence of a common ancestor to many species.