Final answer:
The eukaryotic cell cycle includes G1 (a growth or gap phase), S (DNA synthesis), G2 (a second growth or gap phase), and G0 (a resting or quiescent phase). There are checkpoints at G1, S, and mitosis to ensure cells are ready to proceed through the cycle and divide properly.
Step-by-step explanation:
The eukaryotic cell cycle consists of several phases: G1, S, G2, and G0. During the G1 phase (Growth Phase 1 or Gap 1), the cell grows rapidly, performs routine metabolic processes, makes proteins needed for DNA replication, and duplicates some organelles. The S phase (Synthesis phase) is the period during which the cell replicates its DNA. The G2 phase (Growth Phase 2 or Gap 2) involves final preparations for cell division, such as making additional proteins and organelles. The G0 phase is a resting or quiescent stage where cells may exit the cell cycle and stop dividing. This phase is significant for cells that either have reached their end differentiation state or when conditions are not favorable for division. Key checkpoints in the cell cycle exist to ensure proper division and DNA integrity. The G1 checkpoint determines whether the cell is large enough to divide, the S checkpoint verifies proper DNA replication, and the mitosis checkpoint assures correct chromosome alignment before division.