In mitosis, which stage is characterized by the separation of sister chromatids?

• A. Prophase
• B. Metaphase
• C. Anaphase
• D. Telophase

Answer: (C)

The key event is the stage when the two copies of each chromosome, held together as sister chromatids, are pulled apart toward opposite poles. This happens because the cohesin proteins that glue the chromatids together are cut, allowing them to separate. Microtubules attached to the kinetochores shorten, pulling each chromatid toward a pole, while the spindle poles move farther apart as other microtubules lengthen. By the end of this stage, each pole has a complete set of chromosomes, ready for the chromosomes to de-condense and new nuclei to form in the next steps.