G2 Phase

Definition

The G2 phase is a crucial part of the cell cycle that occurs after DNA synthesis in the S phase and before mitosis. During this phase, the cell undergoes final preparations for division, ensuring that all necessary components are ready, such as proteins and organelles. It serves as a checkpoint, allowing for DNA repair and the confirmation of cell size and energy stores, which are vital for successful cell division.

5 Must Know Facts For Your Next Test

1. The G2 phase typically lasts several hours and is critical for the accuracy of cell division.
2. During G2, the cell checks for DNA damage and can repair any errors before proceeding to mitosis.
3. Cells also increase their size and synthesize proteins necessary for mitosis during the G2 phase.
4. The G2 checkpoint prevents cells with damaged DNA from entering mitosis, thereby reducing the risk of passing on genetic mutations.
5. A failure in the G2 checkpoint can lead to uncontrolled cell division and is associated with cancer development.

Review Questions

• How does the G2 phase contribute to the overall accuracy of cell division?
  • The G2 phase is essential for ensuring that all preparations are complete before a cell enters mitosis. During this phase, the cell checks for DNA integrity, allowing for any necessary repairs. This process ensures that only healthy cells proceed to divide, which is critical for maintaining genomic stability and preventing errors that could lead to diseases like cancer.
• What are the key activities that occur during the G2 phase that prepare a cell for mitosis?
  • During the G2 phase, several key activities take place to prepare the cell for mitosis. The cell synthesizes proteins required for chromosome condensation and spindle formation. It also increases in size, accumulating energy reserves and organelles to ensure that both daughter cells will be adequately equipped after division. These preparations are vital for a successful transition into mitosis.
• Evaluate the importance of the G2 checkpoint in relation to cancer development.
  • The G2 checkpoint plays a significant role in preventing cancer by ensuring that cells with damaged DNA do not proceed to mitosis. If this checkpoint fails, cells may divide despite having genetic errors, leading to mutations being passed to daughter cells. This uncontrolled proliferation is a hallmark of cancer. Understanding this relationship highlights the importance of cellular regulation mechanisms in maintaining health.

Related terms

Cell Cycle: The series of stages that a cell goes through during its life, including growth, DNA replication, and division.

Mitosis:

The process by which a cell divides its nucleus and genetic material to form two daughter cells.

Checkpoint: Control mechanisms in the cell cycle that ensure proper progression through different phases, allowing for repair or halting of the cycle if errors are detected.