Cell Cycle
- Created by: Amy Whitehead
- Created on: 13-12-12 20:34
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- Cell Cycle
- Interphase
- G1 - the cell grows and carries out protein synthesis and other cellular functions.
- S - The cell replicates its DNA. At the completion of this stage, all of the chromosomes have two chromatids
- G2 - the cytoplasmic organelles replicate
- Why is it important?
- Growth – multicellular organisms grow by producing new extra cells. Each new cell is genetically identical to the parent cell, and so can perform the same functions
- Repair – damaged cells need to be replaced by new ones that perform the same functions and so need to be identical
- Asexual Reproduction – single-celled organisms divide to produce two daughter cells that are separate organisms. Some multicellular organisms produce offspring from parts of the parent
- Replacement – Red blood cells and skin cells are replaced by new ones
- Mitosis
- Prophase
- DNA begins to condense into discrete bodies called chromosomes. The nuclear membrane breaks down. Also, centrioles move to opposite sides of the cell and form the spindle fibres.
- Metaphase
- The membrane of the nucleus disintegrates and the chromosomes move to the middle . The chromatids align randomly along the middle of the cell, and the spindle fibres attach to the centromeres.
- Anaphase
- The spindle fibres recoil, pulling the chromatid pairs apart, to each of the poles of the cell. The chromatids are led by centromere.
- Prophase
- The nuclear membrane reforms around the two groups of chromatids, meaning that two new nuclei are formed, surrounding by one cytoplasm.
- 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.
- By the end of mitosis, there are two nuclei in one cytoplasm
- Interphase
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