Suppose a single nondisjunction event occurs during anaphase II of meiosis in a normal male cell from meiosis I. Of the resulting sperm, ____.
A) three would be normal and one would have an extra chromosome
B) two would be normal, one would have an extra chromosome, and one would be missing a chromosome
C) two would have an extra chromosome and two would be missing a chromosome
D) all four sperm would have an extra chromosome
E) three would have an extra chromosome and one would be normal

Question

Suppose a single nondisjunction event occurs during anaphase II of meiosis in a normal male cell from meiosis I. Of the resulting sperm, ____.​
A) ​three would be normal and one would have an extra chromosome
B) ​two would be normal, one would have an extra chromosome, and one would be missing a chromosome
C) ​two would have an extra chromosome and two would be missing a chromosome
D) ​all four sperm would have an extra chromosome
E) ​three would have an extra chromosome and one would be normal

Quizplus · Accepted Answer

Nondisjunction during anaphase II of meiosis results in two normal sperm (with the correct number of chromosomes) and two abnormal sperm: one with an extra chromosome and one missing a chromosome. This is because the chromosomes fail to separate properly, leading to one gamete with an additional chromosome and one with one less.

Suppose a Single Nondisjunction Event Occurs During Anaphase II of Meiosis