In which phase of the cell cycle do cells primarily grow and prepare for DNA replication?

During the cell cycle, the G1 phase is crucial for cellular growth and preparation for DNA replication. In this phase, cells increase in size, produce the necessary organelles, and synthesize proteins that they will need for the next stages of the cycle. The G1 phase serves as a checkpoint for the cell to assess whether conditions are suitable for DNA synthesis. If the cell is healthy, it will proceed to the S phase, where DNA replication actually occurs.

Understanding the G1 phase is essential for recognizing how cells ensure they have the resources and capabilities needed to replicate their DNA accurately and prepare for division. The subsequent phases, such as the S phase and G2 phase, focus on DNA synthesis and further preparation for mitosis, respectively, but it is within the G1 phase that the groundwork is laid.