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MITOSIS. Mitosis and the CELL CYCLE. The life cycle of a cell is called the CELL CYCLE. The cell cycle begins when the cell is formed and ends when the cell divides and forms new cells. Cell division in eukaryotic cells is called MITOSIS. Mitosis.
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Mitosis and the CELL CYCLE • The life cycle of a cell is called the CELL CYCLE. • The cell cycle begins when the cell is formed and ends when the cell divides and forms new cells. • Cell division in eukaryotic cells is called MITOSIS.
Mitosis • Mitosis is a process of cell division that forms two new nuclei; each of which has the same number of chromosomes as the original cell. • Mitosis produces new cells through asexual reproduction. • Asexual reproduction is reproduction that only involves ONE parent cell and produces cells that are genetically identical to the parent cell.
Three reasons why cells reproduce by asexual reproduction: 1. Growth 2. Repair 3. Replacement Cell that reproduce by asexual reproduction reproduce constantly.
Mitosis • Interphase • Prophase • Metaphase • Anaphase • Telophase & Cytokinesis
Interphaseoccurs before mitosis begins • Chromosomes are copied (# doubles) • Chromosomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm
Interphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Prophase 1st step in Mitosis • Mitosis begins (cell begins to divide) • Centrioles(or poles) appear and begin to move to opposite end of the cell. • Spindle fibers form between the poles. • Nucleus begins to disolve. Centrioles Sister chromatids Spindle fibers
Prophase Plant Cell Animal Cell Spindle fibers Centrioles Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Metaphase 2nd step in Mitosis • Chromatids (or pairs of chromosomes) attach to the spindle fibers. • Chromatids line up in the Middle. • “M” for middle- “M” for metaphase!!!! Centrioles Spindle fibers
Metaphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Anaphase 3rdstep in Mitosis • Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. • “A” for away- “A” for anaphase- chromatids move AWAY from the middle! Centrioles Spindle fibers
Anaphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase4th step in Mitosis • Two new nuclei form. • Chromosomes appear as chromatin (threads rather than rods). • Mitosis ends. Nuclei Nuclei Chromatin
Telophase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Cytokinesisoccurs after mitosis • The division of the cytoplasm. • Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical number of chromosomes. • In plant cells a cell plate forms in the middle of the cell, and develops into a new cell wall as the cell splits in two.
IPMATC REMEMBER! • Interphase • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis IPutMy AppleThere Carefully
- Cell Division The Cell Cycle 21
MitosisAnimation http://www.cellsalive.com/mitosis.htm