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21 Cards in this Set
- Front
- Back
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DNA overload
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DNA holds information that controls cell functions. as a cell grows more information is needed and DNA cannot "keep up" with demand.
Analogy: small library in big city. |
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Cell Membrane
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all food, oxygen, water enter cell through membrane; waste products leave cell through membrane.
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As a cell grows the volume ________, but the surface area (cell membrane) only...__________.
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_increases alot
_increases a little. |
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If the cell grows too big, ....
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the membrane can no longer move enough materials in and out to support the cell contents.
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Cells want...
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a LARGE surface area to volume ratio so they have plenty of space to move stuff in and out.
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Small cells have...
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LARGE surface area: volume ratio
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Two main stages of cell divivion?
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Mitosis (division of the nucleus)
Cytokinesis (division of the cytoplasm) |
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Mitosis is used for ....
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-a sexual reproduction in unicellular organisms
-growth development and tissue replacement in multicellular organisms. |
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chromosome=
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coiled up DNA (and protein)
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Most cells have ___ copies of each chromosome.
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2 copies
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Long before a cell divides..
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it replicates its chromosome; the identical "sister chromatids" are attached at the centromere.
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Cell Cycle=
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series of events that cells go through as they grow and divide.
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interphase=
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a phase of a cells life for growth, DNA replication, and preperation for mitosis.
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G1-
S- G2- M- |
-growth, make organelles.
-synthesize (make)copy of DNA -parts for cell division are made -mitosis and cytokinesis |
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Prophase=
P-M-A-T |
=chromosomes became visible centrioles seperate; spindle fibers form; nucleolus and nuclear envelope disappear.
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Metaphase=
P-M-A-T |
= chromosomes line up across center of cell; microtubules connect the centromeres to the spindles.
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Anaphase=
P-M-A-T |
centromeres splitl sister chromatids seperate; seperated chromosomes group near poles of spindle.
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Telephase=
P-M-A-T |
chromosomes disperse; nucleoli and nucleur envelopes reform; spindle breaks apart --> now two nuclei
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Cytokinesis
-occurs directly after... |
telephase
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cyclins-
internal- external- |
-family of proteins; regulate timing of cell cycle in eukaryotic cells.
-respond to events inside the cell. -respond to events outside the cell. |
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Cancer cells...
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do not respond to the signals that regulate the growth of most cells.
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