What is separated in Anaphase II?
The correct answer and explanation is :
In Anaphase II of meiosis, sister chromatids are separated.
Explanation:
Meiosis is a type of cell division that reduces the chromosome number by half, essential for sexual reproduction. It consists of two successive divisions: Meiosis I and Meiosis II. Anaphase II is a stage within Meiosis II, where the separation of genetic material occurs, ensuring that each resulting gamete (egg or sperm) has only one copy of each chromosome.
Meiosis Overview:
Meiosis I is the reductional division, where homologous chromosomes (chromosomes of the same type, one from each parent) are separated. In contrast, Meiosis II is the equational division, where the sister chromatids (identical copies of a chromosome formed during DNA replication) are separated, similar to what happens in mitosis.
Anaphase II:
- During Anaphase I of meiosis, homologous chromosomes are separated. In Anaphase II, the key event is the separation of sister chromatids, which were held together by cohesin proteins.
- The process begins when the centromere, which holds the sister chromatids together, is cleaved. This allows the sister chromatids to be pulled apart toward opposite poles of the cell by the spindle fibers attached to the centromeres.
- The movement of sister chromatids toward the poles ensures that each new cell will receive a single chromatid from each chromosome pair, resulting in haploid cells (cells with half the chromosome number of the original diploid cell).
After Anaphase II:
Following the separation of sister chromatids, the chromatids reach the poles, and the cell moves into Telophase II, where nuclear membranes form around each set of chromatids. Eventually, cytokinesis occurs, leading to the formation of four genetically unique haploid gametes.
This separation of sister chromatids in Anaphase II ensures genetic diversity in offspring, which is a hallmark of sexual reproduction.