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The Cell Cycle

  • The genetic material (DNA) in eukaryotic cells is organized into chromosomes Chromosomes that have been replicated contain two identical sister chromatids connected by a centromere.
  • The two major phases of the cell cycle are the mitotic phase (M phase) and interphase. Interphase is divided into the G1, S and G2 phases. M phase consists of mitosis and cytokinesis.
  • Cytoplasmic signaling molecules regulate the cell cycle. These molecules constitute the cell cycle control system. Checkpoints occur at G1, G2 and the M phase.
  • Cyclins and cyclin dependent kinases (CDKs) are two types of proteins that regulate the cell cycle. Other internal and external signals also regulate the cell cycle.
  • Cancer cells may not wait for the go-ahead signal at checkpoints in the cell cycle. They also exhibit a loss of density dependent inhibition and anchorage dependence.

The Cell Cycle

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AP Biology Intro