Bio. Chapter 8 – Flashcards
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Cancer is not usually inherited because
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the chromosomal changes in cancer are usually confined to somatic cells
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A karyotype is most like
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photographs of every couples at a high school prom
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Strictly speaking, the phrase "like begets like" refers to
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asexual reproduction only
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Which of the following helps maintain the structure of chromosomes and control the activity of genes
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Proteins
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Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
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formation of a cell plate
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Both mitosis and meiosis are preceded by
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Interphase
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Which of the following statements is false?
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An X chromosome is an autosome
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Which of the following shows the greatest promise as a cancer chemotherapy agent?
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a drug that prevents mitotic spindle from forming
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Which of the following occurs during interphase?
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cell growth and duplication of the chromosomes
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Independent orientation of chromosomes at metaphase I results in an increase in the number of
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possible combinations of characteristics
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Which of the following statements regarding Down Syndrome is false?
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Down syndrome is least likely to be seen in the infants of mothers over 40
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Sister chromatids are
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joined together at a centromere
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A benign tumor differs from a malignant tumor in that a benign tumor
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does not metastasize
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Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that the cell is
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undergoing cytokinesis
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At the start of mitotic anaphase,
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the centromeres of each chromosome come apart
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When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of
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density-dependednt inhibition.
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Karyotyping
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can reveal alterations in chromosome number
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Independent orientation of chromosome at metaphase I and random fertilization are most like
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shuffling cards and dealing out hands of poker
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The genetic material is duplicated during
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the S phase
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Which of the following statements about nondisjunction is false?
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In mammals, extra copies of the Y chromosome are typically inactivated
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Which of the following statements regarding cell division is false?
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Cell division is common in eukaryotes but rare in prokaryotes.
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You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem to fail to exhibit density0dependent inhibition. The source of this tissue sample is most likely
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a cancer
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Which of the following statements regarding the function of mitosis is false?
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Mitosis allows organisms to generate genetic diversity.
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During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?
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metaphase
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Which of the following must occur for a plant or animal to grow and develop normally?
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The organism must be able to control the timing and rate of cell division in different parts of its body.
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Which of the following statements regarding the differences between mitosis and meiosis is false?
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Crossing over is a phenomenon that creates genetic diversity during mitosis
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Which of the following statements regarding mitosis and meiosis is false?
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Meiosis provides for asexual reproduction.
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Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are
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homologous chromosomes
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At a chiasma, two _____ are attached to each other.
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Homologous or non-sister chromatids
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During which phase of mitosis does the nuclear envelope re-form?
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telophase
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Which of the following features likely accounts for the difference between plant and animal cell cytokinesis?
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Plant cells have cell walls
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Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition?
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physical contact of cell-surface proteins between adjacent cells.
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Which of the following statements regarding genetic diversity is false?
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Genetic diversity is enhanced by mitosis.
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As a patch of scraped skin heals, the cells fill in the injured area but do not grow beyond that. This is an example of
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density-dependent inhibition
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Which of the following types of organisms commonly demonstrates polyploidy?
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flowering plants
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During which stage of meiosis do synapsis and crossing over occur?
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Prophase I
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Without crossing over
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genetic recombination could not occur
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Mature human nerve cells and muscle cells
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are permanently in a state of nondivision
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The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called
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asexual reproduction
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With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have
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a similar but not identical combination of genes
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Which of the following options correctly describes the behavior of a tetrad during anaphase I of meiosis?
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It splits into two pairs of sister chromatids and one pair goes to each pole of the dividing cell
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If a chromosome fragment breaks off and then reattaches to the original chromosome, but in the reverse direction the resulting chromosomal abnormality is called a(n)
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inversion
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The phase of mitosis during which the mitotic spindle begins to form is
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Prophase
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Asexual reproduction requires _____ individual(s).
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1
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Which of the following statements regarding prokaryotes is false?
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Prokaryotic chromosomes are more complex than those of eukaryotes.
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Which of the following statements regarding sexual and asexual reproduction is true?
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Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.
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How many generations does it take to develop a new plant species by polyploidy?
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One
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Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called
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sister chromatids
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This process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
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cytokinesis
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Eukaryotic chromosomes differ from prokaryotic chromosomes in that they
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are housed in a membrane-encolsed nucleus
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Eukaryotic cells spend most of their cell cycle in which phase?
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Interphase
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Which of the following statements regarding the cell-cycle control system is false?
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The cell-cycle control system operates independently of the growth factors
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Nondisjunction occurs when
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members of a chromosome pair fail to separate
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Which of the following statements regarding mitosis and meiosis is false?
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Mitosis produces daughter cells with half the number of chromosomes as the parent cell
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Which of the following variations of the sentence "Where is the cat" is most like a chromosomal deletion?
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Where is cat?
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A pair of sex chromosomes found in a human male is most like
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a bride and groom
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Independent orientation of chromosomes at metaphase I results in an increase in the number of
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possible combinations of characteristics
