Chapter 12 Biology – Flashcards
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The centromere is a region in which
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Chromatids are attached to one another
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If there are 20 centromeres in a cell, how many chromosomes are there?
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20
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Where do the micro tubules of the spindle originate during mitosis in both plant and animal cells
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Centrosome
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Does not occur during mitosis
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Synthesis of DNA
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1. Condescending of chromosomes 2. Uncoupling of chromatids 3. Formation of a spindle 4. Disappearance of the nucleolus.
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All happen during mitosis
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If a cell had 8 chromosomes at metaphase of mitosis, how many chromatids will it have during anaphase?
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16
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If a cell completed mitosis but not cytokinesis what would the result be
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A cell with two nuclei
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How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cells when it was in g1 of the cell cycle
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Daughter cells have same # of chromosomes and same amount of DNA
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Formation of cell plate is beginning across the middle of a cell and nuclei are reforming at the opposite ends of the cell. What kind of cell is this?
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Plant cell during cytokinesis
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Bacterial centromeres uncouple during replication
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False
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Movement of chromosome during anaphase would be most affected by a drug that
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Prevented shortening of microtubules.
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Cells that are in nondividing state are in
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g0 phase
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What causes the rhythmic change in cyclin concentration in the cell cycle
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It's destruction by an enzyme phosphorylated by MPF
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Released by platelets in the vicinity of an injury
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PDGF
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Enzymes that activate or inactivate other proteins by phosphorylating them
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Protein kinase
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Fibroblasts have receptors for this substance in their plasma membranes
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PDGF
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A protein synthesized through the cell cycle that associates with a kinase to form active enzymes
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Cyclin
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Triggers the cells passage past the g2 check point into mitosis
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MPF
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As the cell progresses through prophase and into metaphase what happens to the active anaphase promoting complex proteins
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They increase sharply once all the chromosomes are lined up in metaphase
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What triggers the separation of chromatids during mitosis
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Activation of an anaphase-promoting complex
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Proteins that are involved in the regulation of the cell cycle and that show fluctuations in concentration during the cel cycle are called
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Cyclins
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The MPF protein complex turns itself on by
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Activating an enzyme that destroys cyclin
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Recent research has indicated that cancer cells
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Transform normal cells by altering genes involved in the control of mitosis
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Cancer cells
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Do not exhibit density dependent inhibition when growing in culture
