G2 Phase

Definition

The G2 phase is the third subphase of interphase in the cell cycle, occurring after DNA synthesis in the S phase and before mitosis. During this phase, the cell undergoes further growth and prepares itself for division, ensuring all cellular components are ready and intact. The G2 phase is crucial for checking DNA replication errors, organizing the cytoskeleton, and synthesizing proteins needed for mitosis.

5 Must Know Facts For Your Next Test

1. During the G2 phase, cells double-check their DNA to make sure there are no replication errors before moving on to mitosis.
2. The length of the G2 phase can vary depending on the type of cell and environmental conditions, influencing how quickly a cell can divide.
3. G2 is characterized by intense metabolic activity where proteins required for mitosis are synthesized and organelles are replicated.
4. Cells can enter a resting state known as G0 if they do not receive signals to proceed through the cell cycle during G1 or G2 phases.
5. If errors are detected during the G2 checkpoint, cells can undergo repair processes or trigger apoptosis if damage is too severe.

Review Questions

• How does the G2 phase contribute to the overall integrity of cellular division?
  • The G2 phase plays a critical role in maintaining cellular integrity by allowing the cell to check for any DNA replication errors that may have occurred during the S phase. This checkpoint ensures that any mistakes can be repaired before the cell enters mitosis. If errors are found and cannot be fixed, mechanisms can induce apoptosis to prevent damaged cells from dividing, which is vital for organismal health.
• Discuss the significance of checkpoints in relation to the G2 phase and cancer development.
  • Checkpoints during the G2 phase are crucial for preventing the progression of damaged cells into mitosis. If these checkpoints fail due to mutations or dysregulation, it can lead to uncontrolled cell division, a hallmark of cancer. Understanding how these checkpoints operate helps in developing cancer therapies aimed at restoring normal regulatory functions to ensure that damaged cells do not continue to proliferate.
• Evaluate how disruptions in the G2 phase could affect tissue homeostasis and overall organism health.
  • Disruptions in the G2 phase can lead to an accumulation of damaged cells that may either divide uncontrollably or fail to divide when necessary. This imbalance can result in tissue dysfunction, contributing to various diseases, including cancer. Moreover, if stem cells or progenitor cells fail to properly regulate their division due to issues in the G2 phase, it could impair tissue repair mechanisms, ultimately affecting overall organism health and resilience.

Related terms

Interphase: The overall phase of the cell cycle where the cell prepares for division, consisting of G1, S, and G2 phases.

Checkpoint: Regulatory mechanisms in the cell cycle that ensure proper progression through each phase by monitoring for errors or damage.

Mitosis: The process of cell division that follows interphase, where duplicated chromosomes are separated into two daughter cells.