1406 bio ch 12 follow up – Flashcards
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Tissue culture experiments with PDGF demonstrate that without this substance __________.
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fibroblasts fail to divide PDGF is a specific growth factor for fibroblasts.
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The decline of MPF activity at the end of mitosis is due to
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The decline of MPF activity at the end of mitosis is due to
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Which of the following codes for proteins?
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genes
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You are developing a new drug that damages the cells that provide the supportive structure required by a tumor. Which type of cell are you targeting?
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fibroblast
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A tumor would not be able to have its own blood supply if it weren't for which of the following?
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immune system cells D. endothelial cells
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Which of the following appears to be true according to current research?
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As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase.
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Nucleoli are present during _____.
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interphase
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Spindle fibers attach to kinetochores during _____.
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prometaphase
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During prophase a homologous pair of chromosomes consists of _____.
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Two chromosomes and four chromatids
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The person credited with first recognizing (in the 1860s) that living cells cannot arise spontaneously, but arise only from previously existing cells, is _____.
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Rudolf Virchow
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An environmental substance that is known to cause cancer is called a what?
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carcinogen
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Radiation emitted from which of the following two sources are most alike?
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microwaves and cellphones
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You are trying to discover if the pesticide atrazine is a mutagen. Where are you looking for mutations?
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DNA
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Which of the following best summarizes current scientific opinion regarding cellphones and brain cancer?
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While most studies indicate that cellphones do not cause brain cancer, more research needs to be done as cellphone use increases.
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The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?
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cleavage furrow formation
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Which of the following is true of kinetochores?
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They are sites at which microtubules attach to chromosomes.
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Which of the following hypotheses is best supported by observing cancer cells in a culture?()
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do not exhibit density-dependent inhibition
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In the cells of some organisms, mitosis occurs without cytoki-nesis. This will result in
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cells with more than one nucleus.
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The function of the mitotic cell cycle is to produce daughter cells that __________.
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are genetically identical to the parent cell (assuming no mutation has occurred) Cell division involves the distribution of identical genetic material (DNA) to two daughter chromosomes.
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Which of the following is a large reason behind the increase in breast cancer in developing countries?
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Women are living longer.
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You are an oncologist specializing in colon cancer. A patient presents to you with disease that has spread to his bones and liver and there is no treatment available. What stage cancer is this?
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4
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A woman in Uganda is diagnosed with breast cancer. If any treatment is done, what is it most likely to be?
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Only a mastectomy.
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You are a breast cancer survivor and advocate in the U.S. Why do you promote self breast exams to women under 50 rather than annual mammograms?
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Women under 50 tend to have denser breast tissue which often make mammograms inconclusive.
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Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells?
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Movement of RNA molecules from the nucleus to the cytoplasm
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In sexually reproducing multicellular organisms, the main functions of mitosis are _____.
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tissue repair/replacement of damaged cells growth and development
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Which events occur during prophase?
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The nuclear envelope breaks down. Chromosomes condense and are attached to spindle fibers.
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Cytokinesis _____.
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finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells
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During _____, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus.
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interphase
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Looking through a light microscope at a dividing cell, you see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing ____
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telophase
