Question

Which of the following statements is false?

a. Nondisjunction occurs when homologous chromosomes fail to separate.
b. Nondisjunction occurs when strands of the same chromosome fail to separate.
c. Nondisjunction can result in a daughter cell with an extra chromosome.
d. Nondisjunction can result in a daughter cell completely lacking a chromosome.
e. Nondisjunction occurs only in mitosis.

Answer 1

The false statement is that nondisjunction occurs only in mitosis. It actually occurs during meiosis, leading to aneuploidy in gametes by affecting homologous chromosomes in meiosis I or sister chromatids in meiosis II.

Step-by-step explanation:

The false statement among the given options is that nondisjunction occurs only in mitosis. In fact, nondisjunction is the process by which homologous chromosomes or sister chromatids fail to separate properly. This can happen during meiosis I, where nondisjunction of homologous chromosomes results in gametes with an abnormal number of chromosomes (aneuploidy), specifically n+1 or n-1. If nondisjunction occurs during meiosis II, it involves sister chromatids that fail to separate, leading to one gamete without the chromosome, two gametes with a single copy (normal), and one gamete with an extra copy (n+1).