Optometry Admission Test (OAT) Practice

What is the main feature of meiosis II compared to meiosis I?

1. It includes DNA replication

2. It results in diploid cells

3. It separates sister chromatids

4. It mixes genetic material from two parents

The correct answer is: It separates sister chromatids

Meiosis II is characterized primarily by the separation of sister chromatids. This phase of meiosis resembles a typical mitotic division, where the sister chromatids, which are the duplicated copies of each chromosome, are pulled apart into individual chromosomes. This separation leads to the formation of haploid cells from the four daughter cells produced after the two meiotic divisions. In contrast, meiosis I is when homologous chromosomes are separated, resulting in two haploid cells that each contain duplicated chromosomes. As such, the process of meiosis II is critical for ensuring that each gamete receives only one copy of each chromosome, which is essential for sexual reproduction. Understanding this distinction is crucial because it highlights the different roles that each phase plays in genetic diversity and the reduction of chromosome number in gametes. Meanwhile, DNA replication occurs only once prior to meiosis, during the S phase of Interphase, and does not occur again in meiosis II. The resultant cells from meiosis II are haploid, not diploid. Mixing genetic material occurs during crossing over in prophase I, not during meiosis II.