Download chapter 4.2 notes – the cell cycle

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CHAPTER 4.2 NOTES – THE CELL CYCLE
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All cells come from pre-existing cells.
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The CELL CYCLE is the stages of growth and reproduction for the cell.
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The main events in the life of a cell are:
1. GROWTH
2. SYNTHESIS
3. MITOSIS
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The four phases of the cell cycle are:
1. GROWTH 1
2. SYNTHESIS
3. GROWTH 2
4. MITOSIS
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Before a cell can divide, it must REPLICATE/COPY its DNA.
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INTERPHASE includes G1, S, G2 phases; it prepares the cell to divide.
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G2: cell grows larger, makes proteins and organelles.
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S phase is known as the synthesis phase; DNA replicates making 2 strands.
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M (MITOSIS): cell prepares to divide.
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MITOSIS results in the formation of 2 DIPLOID DAUGHTER cells.
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There are 4 Stages of Mitosis:
1. PROPHASE
2. METAPHASE
3. ANAPHASE
4. TELOPHASE
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Prophase: the NUCLEUS breaks apart and chromosomes and spindle fibers form.
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METAPHASE: the shortest phase of mitosis; spindle fibers attach to the chromosomes that are lining
up in the middle of the cell.
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ANAPHASE: the second shortest phase of mitosis; sister chromatids are pulled APART.
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Telophase: the NUCLEUS starts to reappear, chromosomes shrink, and spindle fibers break apart.
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CYTOKINESIS is the last stage of the cell cycle. This is the division of the CYTOPLASM and the two
separate cells are now formed.