Consider the abbreviated model of meiosis. The end result of meiosis should be the production of four haploid gametes. In this example, an error has taken place. Describe and name this error.

Question

Responses
A Nondisjunction of sister chromatids during meiosis II. Sister chromatids fail to separate.Nondisjunction of sister chromatids during meiosis II. Sister chromatids fail to separate.
B Translocation of sister chromatids during meiosis II. One chromatid is translocated into incorrect cell.Translocation of sister chromatids during meiosis II. One chromatid is translocated into incorrect cell.
C Separation mutation during meiosis I. Resulting gametes in meiosis II have incorrect chromosome number at end of meiosis.Separation mutation during meiosis I. Resulting gametes in meiosis II have incorrect chromosome number at end of meiosis.
D Replication error during meiosis I. Results of mutation show during meiosis II as incorrect chromosome number in two gametes.

Answer 1

The error described in this scenario is best represented by option A: Nondisjunction of sister chromatids during meiosis II. Sister chromatids fail to separate.

Nondisjunction refers to the failure of homologous chromosomes or sister chromatids to separate properly during cell division. If nondisjunction occurs during meiosis II, it can lead to gametes that either have an extra chromosome (n+1) or are missing a chromosome (n-1), ultimately leading to an incorrect chromosome number in the resulting gametes. In the context of meiosis, this is a critical error as it can lead to aneuploidy in the resultant zygotes after fertilization.