Which of the following is most likely to occur during prophase II of meiosis?

• A. The nuclear envelope reforms around separated chromosomes.
• B. Sister chromatids are pulled apart toward opposite poles.
• C. Homologous chromosomes pair and crossing over occurs.
• D. Chromosomes condense and a new spindle apparatus forms in each haploid cell.

Answer: (D)

Verified step by step guidance

1. Step 1: Recall the stages of meiosis and their key events. Meiosis consists of two divisions: meiosis I and meiosis II. Prophase II occurs after meiosis I, which separates homologous chromosomes, leaving haploid cells.
2. Step 2: Understand the purpose of prophase II. In this stage, the cell prepares for the second division, which will separate sister chromatids. This is distinct from prophase I, where homologous chromosomes pair and crossing over occurs.
3. Step 3: Note that during prophase II, chromosomes condense again. This condensation is necessary to ensure proper attachment to the spindle apparatus and accurate segregation during the subsequent division.
4. Step 4: Recognize that a new spindle apparatus forms in each haploid cell during prophase II. This spindle apparatus is crucial for aligning and separating sister chromatids during metaphase II and anaphase II.
5. Step 5: Eliminate incorrect options based on the events of prophase II. For example, the nuclear envelope reforms during telophase, sister chromatids are pulled apart during anaphase II, and homologous chromosomes pair and crossing over occurs during prophase I, not prophase II.