Chapter 12 Outline - Summary Campbell Biology PDF

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Chapter 12: The Cell Cycle 12.1 “Cell division results in genetically identical daughter cells 

Cell division involves the distribution of identical genetic material—DNA—to two daughter cells

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A typical human has 2 m of DNA

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Somatic Cells contain 46 chromosomes (2 sets of 23)

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Gametes (sex cells) have one set of 23

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Mitosis is the division of nucleus

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Cytokinesis is the division of cytoplasm

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Meiosis yields nonidentical daughter cells that only have one set of chromosomes

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Meiosis only occurs in your gonads (ovaries or testes) 12.2 “The mitotic phase alternates with interphase in the cell cycle”

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M phase includes both mitosis and cytokinesis, and is usually the shortest part of the cell cycle

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Interphase takes up 90% of the cycle

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Interphase includes G1 Phase, S phase, and G2 Phase

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A typical human cell might undergo one division in 24 hours

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Mitosis is broken down into 5 parts: prophase, prometaphase, metaphase, anaphase, and telophase

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Many of the events of mitosis depend on the mitotic spindle

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The assembly of spindle microtubules starts at the centrosome

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Cytokinesis is different in plant cells, since they have cell walls. There is no cleavage furrow. They form a cell plate instead

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Prokaryotes reproduce by a type of cell division called binary fission

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Most genes in bacteria are carried on a single bacterial chromosome that consists of a circular DNA molecule and associated proteins 12.3 “The cell cycle is regulated by a molecular control system”

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The timing and rate of cell division in different parts of a plant or animal are crucial to normal growth, development, and maintenance

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The frequency of cell division varies with the type of cell

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Cell cycle control system triggers and coordinates key events in the cell cycle

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Check points are a critical control point where stop and go signals are given

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The G1 checkpoint is usually dubbed the most important

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Mature nerve cells and muscle cells never divide

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For kinases to be in an active form, they have to be attached to a cyclin

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A growth factor is a protein released by certain cells that stimulates other cells to divide

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Most benign tumors do not cause serious problems and can be removed by surgery

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A malignant tumor becomes invasive enough to impair the functions of one or more organs. If a person has this tumor, it is said they have cancer

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A tumor that appears to be localized may be treated with high-energy radiation...