During which phase does the second round of genetic variation occur during meiosis?

• A. Prophase II
• B. Metaphase I
• C. Prophase I
• D. Anaphase I

Answer: (A)

Verified step by step guidance

1. Understand that meiosis is a type of cell division that reduces the chromosome number by half and results in the production of gametes. It consists of two consecutive divisions: meiosis I and meiosis II.
2. Recall that genetic variation during meiosis occurs primarily through two mechanisms: crossing over and independent assortment. Crossing over occurs during prophase I, where homologous chromosomes exchange genetic material.
3. Recognize that the first round of genetic variation occurs during prophase I due to crossing over, which creates new combinations of alleles on each chromosome.
4. Identify that the second round of genetic variation occurs during metaphase I, where independent assortment takes place. This is when homologous chromosomes line up at the metaphase plate and are separated randomly into daughter cells.
5. Conclude that prophase II does not involve a new round of genetic variation. Instead, it prepares the cell for the second meiotic division, where sister chromatids are separated.