During which phase do chromosomes duplicate?

During which phase do chromosomes duplicate?

• A. G1 phase
• B. S phase
• C. G2 phase
• D. Telophase

Answer: (B)

Chromosomes duplicate during the S phase of the cell cycle, which is the synthesis phase. This critical phase follows the G1 phase, where the cell grows and prepares for DNA replication. During the S phase, each chromosome is replicated, resulting in two sister chromatids for each chromosome. This duplication is essential for genetic continuity, ensuring that when the cell divides, each daughter cell will receive an identical set of chromosomes. In contrast, the G1 phase focuses on cell growth and normal metabolic processes without DNA replication. The G2 phase occurs after the S phase and involves further growth and preparation for mitosis, including the production of proteins and organelles necessary for cell division. Telophase, which occurs after mitosis, is the stage where the chromosomes are at opposite poles of the cell and start to de-condense back into chromatin, followed by the division of the cytoplasm. Therefore, S phase is distinctly recognized for the duplication of chromosomes, making it the correct answer.

Chromosomes duplicate during the S phase of the cell cycle, which is the synthesis phase. This critical phase follows the G1 phase, where the cell grows and prepares for DNA replication. During the S phase, each chromosome is replicated, resulting in two sister chromatids for each chromosome. This duplication is essential for genetic continuity, ensuring that when the cell divides, each daughter cell will receive an identical set of chromosomes.

In contrast, the G1 phase focuses on cell growth and normal metabolic processes without DNA replication. The G2 phase occurs after the S phase and involves further growth and preparation for mitosis, including the production of proteins and organelles necessary for cell division. Telophase, which occurs after mitosis, is the stage where the chromosomes are at opposite poles of the cell and start to de-condense back into chromatin, followed by the division of the cytoplasm. Therefore, S phase is distinctly recognized for the duplication of chromosomes, making it the correct answer.