The Cell Cycle
- Created by: Hannah
- Created on: 05-02-13 16:18
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- THE CELL CYCLE
- INTERPHASE
- G1- The cell grows and carries out protein synthesis and other cellular functions.
- S- The cell replicates all of it's DNA. At the end of this stage all of the chromosomes have two chromatids.
- G2- The cytoplasmic organelles replicate and the cell keeps growing, proteins needed for cell division are made.
- MITOSIS
- Prophase
- Metaphase
- Anaphase
- Telophase
- Chromatids reach opposite poles on spindle, uncoil and become chromosomes again. Nuclear envelope forms around each group of chromosomes so there are now two nuclei.
- Centromere's divide separating each pair of sister chromatids. The spindle's contract, pulling chromatids to opposite ends of cell.
- Telophase
- The chromosomes line up along the middle of the cell and become attached to the spindle by their centromere.
- Anaphase
- Chromosomes condense. Centrioles move to opposite ends of the cell, form protein fibres called spindle. Nuclear envelope breaks down.
- Metaphase
- Prophase
- CYTOKINESIS
- By the end of mitosis there are two nuclei in one cytoplasm.
- During cytokinesis the cytoplasm surrounding the two nuclei splits forming two separate genetically identical cells.
- CANCER
- Cancer is the result of uncontrolled cell division caused by mutations (changes in the base sequence of DNA), these cells form tumours
- Some cancer treatments disrupt the cell cycle.
- G1 phase- chemotherap prevents the synthesis of enzymes needed for DNA replication. This means cell cant enter the S phase.
- S phase- Radiation and some drugs damage DNA so when the cell gets into the S-phase it detects damaged DNA and kills itself.
- INTERPHASE
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