Put the following in order: G2, G1, S, Mitosis, Cytokinesis.
The Correct Answer and Explanation is:
The correct order of the phases is: G1, S, G2, Mitosis, Cytokinesis.
Explanation:
Cell division is a highly regulated process that ensures the proper replication and distribution of a cell’s genetic material to two daughter cells. The cell cycle consists of a series of stages that cells go through to grow and divide. These stages are broadly divided into Interphase (which includes G1, S, and G2 phases) and M phase (which includes Mitosis and Cytokinesis).
- G1 (Gap 1 phase): This is the first phase of interphase. During G1, the cell grows in size, produces RNA, and synthesizes proteins necessary for DNA replication. This phase is critical as the cell checks its internal environment and decides whether to proceed to DNA synthesis or enter a resting state (G0). The G1 phase is where cells increase in size and prepare for the next step, which is DNA replication.
- S phase (Synthesis phase): In this phase, DNA replication occurs. Each chromosome duplicates to form two sister chromatids that are attached at a region called the centromere. By the end of the S phase, the cell has double the amount of DNA, ensuring that each daughter cell will receive a complete set of genetic instructions.
- G2 (Gap 2 phase): After DNA replication, the cell enters G2, where it continues to grow and produce proteins. The cell also checks to ensure that DNA replication has occurred correctly without errors or mutations. This phase is the final checkpoint before the cell enters mitosis.
- Mitosis (M phase): Mitosis is the process of nuclear division, where the replicated chromosomes are separated into two identical sets. Mitosis itself is divided into several stages: prophase, metaphase, anaphase, and telophase. This ensures that each daughter cell will receive an identical copy of the genome.
- Cytokinesis: This is the final stage of the cell cycle, where the cytoplasm divides, creating two distinct daughter cells. Cytokinesis usually occurs immediately after mitosis, completing cell division.
Each phase is essential for the accurate replication and division of the cell, ensuring genetic stability across generations of cells.