Describe the main events in each stage of a cell cycle
The correct answer and explanation is:
The cell cycle consists of several phases that a cell goes through to divide and produce two daughter cells. These stages are G1, S, G2, and M phase, each having distinct events that ensure proper cell division.
G1 Phase (Gap 1):
During the G1 phase, the cell grows in size and carries out its normal metabolic activities. The cell synthesizes proteins and RNA necessary for DNA replication. It also prepares for DNA synthesis by accumulating the resources needed. The G1 checkpoint ensures that the cell is ready to proceed to the S phase. If the cell detects any DNA damage or errors, it can enter a resting state called G0.
S Phase (Synthesis):
In the S phase, DNA replication occurs. The cell’s DNA is duplicated, so each chromosome consists of two sister chromatids. This phase is crucial because it ensures that the cell’s genetic material is accurately copied for cell division. The S phase also requires the synthesis of enzymes and proteins that help in DNA replication.
G2 Phase (Gap 2):
The G2 phase is a period of preparation for mitosis. The cell continues to grow, and proteins necessary for cell division are synthesized. During this phase, the cell checks its replicated DNA for any errors or damage. The G2 checkpoint ensures that the cell is ready to enter mitosis, making sure that the DNA replication process is complete and correct.
M Phase (Mitosis):
Mitosis is the phase where the cell divides. It consists of several sub-stages: prophase, metaphase, anaphase, and telophase. During mitosis, the cell’s chromosomes are segregated into two sets, ensuring each daughter cell receives an identical copy of the DNA. After mitosis, cytokinesis occurs, where the cytoplasm divides, resulting in two daughter cells.
The proper progression through these phases is tightly regulated by checkpoints to ensure healthy cell division and function.