Canadian National Institute of Health (CNIH) Entrance Practice Exam

The main event during the G2 phase of the cell cycle involves the cell checking duplicated chromosomes for errors and making any necessary repairs. This phase occurs after DNA replication in the S phase and before the cell enters mitosis. The significance of this process lies in ensuring that any mistakes that happened during DNA replication are corrected, which is crucial for maintaining genomic integrity and preventing the propagation of damaged DNA to daughter cells. By having a specific phase dedicated to this quality control, the cell significantly reduces the risk of mutations and maintains proper cellular function.

This phase also involves preparing the cell for division, but the critical aspect is the verification and repair of the duplicated chromosomes. Other processes like organelle synthesis or entering apoptosis do not take precedence in this phase, as the primary focus is on ensuring that the chromosomes are intact and ready for the next stage of cell division.