A patient's karyotype indicates a chromosome number of 45. This result is best explained by
A) nondisjunction in either the sperm cell or oocyte.
B) nondisjunction in both the sperm cell and oocyte.
C) fertilization of a single oocyte by two sperm cells.
D) a point mutation that caused one or more chromosomes to fuse.

Question

Quizplus · Accepted Answer

Nondisjunction in either the sperm cell or oocyte can lead to an abnormal number of chromosomes, such as 45, due to the failure of chromosomes to separate properly during meiosis. This results in gametes with an abnormal chromosome number, which, when fertilized, can lead to a zygote with an abnormal chromosome count.

A Patient's Karyotype Indicates a Chromosome Number of 45