During anaphase II of meiosis, which of the following events occurs?

• A. The nuclear envelope reforms around chromosomes.
• B. Sister chromatids are separated and pulled toward opposite poles.
• C. Homologous chromosomes pair and exchange genetic material.
• D. Chromosomes condense and become visible for the first time.

Answer: (B)

Verified step by step guidance

1. Understand the context of meiosis: Meiosis is a type of cell division that reduces the chromosome number by half, creating four haploid cells. It consists of two stages: meiosis I and meiosis II. Anaphase II occurs during meiosis II.
2. Recall the key events of anaphase II: During anaphase II, sister chromatids (which were previously attached at the centromere) are separated and pulled toward opposite poles of the cell by the spindle fibers.
3. Eliminate incorrect options: The nuclear envelope reforms around chromosomes during telophase, not anaphase II. Homologous chromosomes pair and exchange genetic material during prophase I, not anaphase II. Chromosomes condense and become visible during prophase, not anaphase II.
4. Focus on the correct event: The separation of sister chromatids is the defining characteristic of anaphase II, distinguishing it from anaphase I, where homologous chromosomes are separated.
5. Summarize the process: In anaphase II, the spindle fibers shorten, pulling the sister chromatids apart to opposite poles of the cell, ensuring that each daughter cell receives a single copy of each chromosome.