Understanding the Cell Cycle Phases

• The cell cycle is a series of four phases: G1, S, G2, and M.
• In G1 phase, the cell is diploid and contains two copies of each chromosome.
• In S phase, each chromosome is duplicated and the sister chromatid pairs remain together as a sister chromatid pair.
• At the end of S phase, each homologous chromosome exists as a sister chromatid pair, thus the cell now contains four copies of each chromosome.
• Next, in G2 phase, the two identical chromosomes separate and the cell enters M phase.
• The final phase of the cell cycle is M phase, or mitosis, in which the duplicated chromosomes separate and the cell divides into two daughter cells.
• During mitosis, the spindle apparatus directs the sister chromatids to align in the equatorial plane of the cell.
• Telophase is the last stage of mitosis and ends with cytokinesis, the splitting of the cytoplasmic membrane and cell contents to form two daughter cells.

Test your knowledge of the cell cycle phases including G1, S, G2, and M, and the processes that occur in each phase such as chromosome duplication and separation during mitosis. Explore the key events that lead to the formation of two daughter cells at the end of the cell cycle.