During which phase of meiosis do chromosomes duplicate and form two identical sister chromatids?

During which phase of meiosis do chromosomes duplicate and form two identical sister chromatids?

• A. Interphase 1
• B. Prophase 1
• C. Telophase 1
• D. Metaphase 1

Answer: (A)

The correct answer is that chromosomes duplicate and form two identical sister chromatids during interphase, specifically in the S (synthesis) phase of interphase prior to the start of meiosis. During this phase, the cell undergoes a series of preparations to ensure that each daughter cell will receive an identical set of chromosomes. The duplication of chromosomes results in the formation of sister chromatids, which are crucial for the proper segregation of genetic material during meiosis. In the subsequent phases of meiosis, such as prophase 1, metaphase 1, and telophase 1, the already duplicated chromosomes (now consisting of two sister chromatids) undergo various processes such as synapsis, alignment along the metaphase plate, and separation. However, it is solely during interphase prior to meiosis that the actual duplication occurs, making it critical for ensuring genetic continuity and variation during sexual reproduction.

The correct answer is that chromosomes duplicate and form two identical sister chromatids during interphase, specifically in the S (synthesis) phase of interphase prior to the start of meiosis. During this phase, the cell undergoes a series of preparations to ensure that each daughter cell will receive an identical set of chromosomes. The duplication of chromosomes results in the formation of sister chromatids, which are crucial for the proper segregation of genetic material during meiosis.

In the subsequent phases of meiosis, such as prophase 1, metaphase 1, and telophase 1, the already duplicated chromosomes (now consisting of two sister chromatids) undergo various processes such as synapsis, alignment along the metaphase plate, and separation. However, it is solely during interphase prior to meiosis that the actual duplication occurs, making it critical for ensuring genetic continuity and variation during sexual reproduction.