Cell Cycle Flashcards

G1 Phase

• Cell grows normally or rests.
• Chromosomes start to thicken.
• G1 Checkpoint Questions:
  • Is the cell big enough?
  • Is the environment favorable?
  • Is the DNA damaged or intact?
• If any question is NO, the cell enters a resting period (G0).

S (Synthesis) Phase

• Cell duplicates all DNA, organelles, and proteins in preparation for division.

G2 Phase

• Cell continues to grow.
• Centrioles double, and spindle fibers start to develop.
• G2 Checkpoint Questions:
  • Have we completed DNA replication?
  • Is the environment favorable?
  • Is the cell big enough?
• If all answers are YES, the cell proceeds to mitosis.

Mitosis

• Includes prophase, metaphase, anaphase, and telophase (P, M, A, T).
• Chromosomes line up at the equator and separate at the centromere.
• Mitosis Checkpoint Questions:
  • Are all chromosomes aligned at the equator?
  • Is there any misalignment?
• If all systems are go, the cell divides.

Checkpoints

• G1 Checkpoint: Cell Growth Checkpoint.
• G2 Checkpoint: DNA Synthesis Checkpoint.
• Metaphase Checkpoint: Mitosis Checkpoint.
• Checkpoints ensure normal cell activities; failure to pass leads to cell death.