What are the primary functions of the G1 and G2 phases of the cell cycle?

The G1 and G2 phases of the cell cycle serve as critical preparatory stages that ensure the cell is ready for mitosis. During the G1 phase, the cell grows and synthesizes proteins necessary for DNA replication. It also assesses its environment and internal conditions to determine if it is suitable to proceed with division. Key processes such as organelle duplication and metabolic activity occur in this phase, setting the stage for the subsequent S phase, where DNA replication takes place.

In the G2 phase, the cell continues to grow and prepares for mitosis by synthesizing proteins that are crucial for chromosome separation and cell division. It also conducts DNA repair mechanisms, ensuring that the genetic material is intact before the cell divides. This phase ensures that all cellular components are ready for the complex processes of mitosis, keeping the cell cycle regulated and reducing the risk of errors.

The other choices do not accurately reflect the roles of the G1 and G2 phases. The separation of chromatids occurs later during mitosis, while excessive cell growth and DNA breakdown are not characteristic of these preparatory phases. Formation of a cleavage furrow is specifically a part of the cytokinesis stage, which follows mitosis. Therefore, the G1 and G2 phases are indeed primarily