Ch 9 mastering biology – Flashcards
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During _____ both the contents of the nucleus and the cytoplasm are divided.
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the mitotic phase
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During _____ the cell grows and replicates both its organelles and its chromosomes.
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interphase
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Which of the following is a function of the S phase in the cell cycle?
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The synthesis of sister chromatids
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The copying of chromosomes occurs during which of the following phases of the cell cycle?
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S phase
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For the first several divisions of early frog embryos, cells proceed directly from the M phase to the S phase and back to M without gaps. Which of the following is likely to be true about dividing cells in early frog embryos?
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The cells get smaller with each generation
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True or false? The M phase is characterized by the replication and division of a cell's chromosomes.
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False
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If an organism normally has 34 chromosomes, how many molecules of DNA should there be in the G1 phase of the cell cycle?
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34
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Which of the following events would cause the cell cycle to arrest?
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Poor nutrient conditions
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Nucleoli are present during _____.
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Interphase
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Cytokinesis often, but not always, accompanies _____.
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telophase
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Chromosomes become visible during _____.
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prophase
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Centromeres divide and sister chromatids become full-fledged chromosomes during _____.
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anaphase
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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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DNA replication produces two identical DNA molecules, called _________, which separate during mitosis
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sister chromatids
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After chromosomes condense, the ___________ is the region where the identical DNA molecules are most tightly attached to each other.
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centromeres
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During mitosis, microtubules attach to chromosomes at the ____________.
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kinetochore(s)
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In dividing cells, most of the cell's growth occurs during ____________.
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interphase
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The ____________ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division
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mitotic spindle(s)
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During interphase, most of the nucleus is filled with a complex of DNA and protein in a dispersed form called ___________.
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chromatin
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In most eukaryotes, division of the nucleus is followed by __________, when the rest of the cell divides
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cytokinesis
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The __________ are the organizing centers for microtubules involved in separating chromosomes during mitosis
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centrosomes
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During prophase, the microtubules of the mitotic spindle __________.
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lengthen
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During anaphase, the nonkinetochore microtubules __________ and move past each other, and the kinetochore microtubules _________.
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lengthen, shorten
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During telophase, the nonkinetochore microtubules _________.
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disassemble
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Which of these is NOT a carcinogen? A. fat B. UV light C. testosterone D. cigarette smoke E. all of the above are carcinogens
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E
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_____ is a carcinogen that promotes colon cancer.
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fat
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Prior to this new technique, how were mice given cancerous tumors?
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The tumors were implanted under the skin
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You are an oncologist. A patient presents with advanced prostate cancer and you follow standard protocol. What do you do?
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The patient is treated with chemical castration
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You are an endocrinologist studying new treatments for prostate cancer. You have a patient with an unusually large level of dihydrotestosterone. Which of the following is true?
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Your patient's cancer has become resistant to the standard treatment
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Which of the following is true regarding prostate cancer cells?
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They can activate and inactivate certain genes
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Your uncle has prostate cancer. Which of the following indicates improvement in his condition?
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A decreasing PSA
