Chapter 6 Learning Curve – Flashcards
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Which of the following correctly orders the events of the eukaryotic cell cycle? DNA synthesis, mitosis, cytokinesis, gap 1, gap 2 Gap 1, gap 2, mitosis, DNA synthesis, cytokinesis Mitosis, gap 1, gap 2, cytokinesis, DNA synthesis Cytokinesis, mitosis, DNA synthesis, gap 1, gap 2 Gap 1, DNA synthesis, gap 2, mitosis, cytokinesis
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Gap 1, DNA synthesis, gap 2, mitosis, cytokinesis
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Cancer cells differ from normal cells in two important aspects. They are: indefinite cell division and the loss of contact inhibition. loss of contact inhibition and the halting of all cell division. a halting of all cell division and the ability to metastasize. apoptosis and contact inhibition. the ability to metastasize and retention of contact inhibition.
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indefinite cell division and the loss of contact inhibition.
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In multicellular organisms, cells that undergo mitotic division but not meiotic division are called _____ cells. skin somosis interphase somatic germ
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somatic
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Sister chromatids are: identical molecules of DNA resulting from replication. the result of crossing over. homologous chromosomes. single-stranded. produced in meiosis but not in mitosis.
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identical molecules of DNA resulting from replication.
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Which of the following is TRUE about sex determination in humans? One would expect babies to have two Y chromosomes about half the time. Without a Y chromosome, a fertilized egg usually dies. The father's sperm determines the gender of a baby. An X chromosome is smaller than a Y chromosome. In the absence of a Y chromosome, the fetal gonads develop into ovaries, not testes.
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The father's sperm determines the gender of a baby.
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_________ marks the break in the cell cycle between the end of mitosis and beginning of the synthesis stage. Gap 1 cytokinesis DNA Synthesis phase Gap 2 None of the above.
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Gap 1
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Programmed cell death, or __________, takes place particularly in parts of the body where the cells are likely to accumulate significant genetic damage over time and are therefore at high risk of becoming cancerous.
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Apoptosis
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Which of the following does NOT occur during Prophase I of meiosis? A protein structure called a synaptonemal complex forms between the homologues. Crossing over between tetrads occurs. Homologous pairs of chromosomes separate and move toward the poles. Chromosomes begin to condense. Spindle is formed.
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NOT - Homologous pairs of chromosomes separate and move toward the poles.
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Which of the following combinations of sex chromosomes is never seen in human being? X_ (also written as XO) YYY XYY XXY XXX
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YYY
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Odometer is to an old, rusty car as __________ is to __________. DNA replication; cell division telomere; a cell after 50 cell divisions circular chromosome; linear chromosome asexual reproduction; sexual reproduction binary fission; mitosis
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telomere; a cell after 50 cell divisions
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Using a light microscope, it is easiest to see chromosomes: during interphase because they are uncoiled and have a more linear structure. during mitosis and meiosis because the condensed chromosomes are thicker and therefore more prominent. during asexual reproduction. in the mitochondria because they are circular. during interphase when they are concentrated in the nucleus.
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during mitosis and meiosis because the condensed chromosomes are thicker and therefore more prominent.
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Which of the following is the best way to distinguish male from female? Males are more brightly colored. Males are more aggressive. Males produce motile gametes. Males are larger. All of the above are correct.
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Males produce motile gametes.
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A karyotype reveals: the number, shapes, and sizes of chromosomes in an individual cell. the number of genes in an individual cell. the sex chromosomes but not the non-sex chromosomes. the non-sex chromosomes but not the sex chromosomes. Both the first and second choices are correct.
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the number, shapes, and sizes of chromosomes in an individual cell.
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If DNA replication occurs by unwinding and rebuilding, then: the two resulting DNA molecules are an unpredictable mixture of old and newly synthesized DNA. the two resulting DNA molecules each contain one original strand and one new strand. the two resulting DNA molecules are completely composed of newly synthesized strands. both A and B are true. None of the above is true about DNA replication.
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b) the two resulting DNA molecules each contain one original strand and one new strand.
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Joseph went to a copy center and used a copy machine to make a duplicate set of 46 pages. Joseph then stapled every copied sheet to its original. This is similar to how a cell replicates its chromosomes in mitosis. For what reason would a cell do something similar during mitosis? To keep the cell from making too many copies of a particular chromosome To keep the copies and originals organized for later separation To keep the cell from dividing too early To introduce helpful mutations that make mitosis more successful To allow the cell to move onward into gap 1 phase
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To keep the copies and originals organized for later separation
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Which of the following is NOT a disadvantage of sexual reproduction? Sexual reproduction breaks down genotypes that are well-adapted for a stable environment. The transfer of genetic information from generation to generation is not as efficient as it is during asexual reproduction. Variability among offspring enables parents to produce a range of offspring, any one of which may be suitable to changes in the environment. It takes time and energy to find a mating partner. Organisms can expose themselves to danger during the mating process.
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Variability among offspring enables parents to produce a range of offspring, any one of which may be suitable to changes in the environment.
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Which of the following conditions is the result of too few sex chromosomes. Turner syndrome Klinefelter syndrome "Super Males" Down syndrome "Metafemales"
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Turner Syndro
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Binary fission is to asexual reproduction as __________ is to __________. mitosis; meiosis dividing into two; genetically identical offspring dividing into two; genetically different offspring dividing into four; genetically different offspring meiosis; mitosis
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dividing into two; genetically identical offspring
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The float in a toilet tank stops the filling of the tank when the water reaches a certain level. If this float is damaged so that it sinks instead, the water would overflow the tank after a flush. This scenario is similar to which of the following cellular concepts? Loss of contact inhibition Increase in cell suicides Loss of the ability to perform mitosis The lengthening of telomeres Failure of cancer cells to metastasize
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Loss of contact inhibition
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Which of the following is TRUE about sexual reproduction? Sexual reproduction produces a greater variation in offspring than asexual. Sexual reproduction requires less energy than asexual reproduction. Sexual reproduction always produces more offspring than asexual reproduction. Sexual reproduction is less risky to the parents than asexual reproduction. Sexual reproduction produces identical offspring compared to the parents.
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Sexual reproduction produces a greater variation in offspring than asexual.
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Which of the following is NOT a known mechanism of sex determination? Eggs that are kept hot during incubation become females; otherwise, the egg is male. Males develop from eggs with no chromosomes, females from diploid eggs. Females develop from diploid (fertilized) eggs, while males develop from haploid (unfertilized) eggs. Females have two different chromosomes (WZ), while males have two of the same chromosome (ZZ). An individual is both male and female at the same time, having gonads for each sex.
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Males develop from eggs with no chromosomes, females from diploid eggs.
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Sister chromatids line up at the center of the cell during which phase of mitosis. Metaphase Interphase Prophase Anaphase Telophase
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Metaphase
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Which of the following explains the fact that the Y chromosome carries nonessential information? Women don't have a Y chromosome and are not genetically disadvantaged. Sperm contribute no genetic information to the egg in fertilization. Males are not needed in sexually reproducing species. Eggs that are not fertilized can still develop into normal human being. A man who inherits two or three Y chromosomes as a result of an error in meiosis is fully normal.
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Women don't have a Y chromosome and are not genetically disadvantaged.
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Which of the following is the direct product of DNA replication? The two strands in a DNA helix The lining up of chromosomes in mitosis metaphase Cytokinesis Two sister chromatids The production of two spindle fibers
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Two sister chromatids
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Which of the following is TRUE about prokaryotic reproduction? It is a form of sexual reproduction. A single circular DNA helix is replicated into two identical circular DNA helices. Mitosis is used. Four cells are produced from a single parent cell. The chromosomes wind up into tight packages before cellular division.
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A single circular DNA helix is replicated into two identical circular DNA helices.
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Which of the following statements about tumors is incorrect? Malignant tumors shed cancer cells that can spread to other parts of the body. They contain cells with abnormally high contact inhibition. Benign tumors pose less of a health risk than do malignant tumors. Tumors are caused by excessive cell growth and division. Cancer cells from malignant tumors can travel to other parts of the body in a process call metastasis.
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False They contain cells with abnormally high contact inhibition.
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Mitosis results in: eight daughter cells. gametes. daughter cells with the same number and composition of chromosomes. daughter cells with the same number of chromosomes but different combinations of alleles. daughter cells with twice as much genetic material and a unique collection of alleles.
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daughter cells with the same number and composition of chromosomes.
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Which of the following is TRUE about meiosis in men and women? The egg is motile, while the sperm is not. Sperm production results in four cells from one starting cell; for eggs, only one egg results from one starting cell. In egg production, the division of cells in meiosis produces cells of equal size. Sperm are larger in size than eggs. Women make sperm, while men make eggs.
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Sperm production results in four cells from one starting cell; for eggs, only one egg results from one starting cell.
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Without histones, eukaryotic DNA most likely would be: much more tightly coiled. circular, as it is in prokaryotes. much longer than it is. found in a greater number of chromosomes. attached to a large number of stick proteins.
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much longer than it is.
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During meiosis but NOT during mitosis: genetic variation among the daughter cells is increased. two identical daughter cells are produced. chromosomes line up in the center of the cell during metaphase. diploid cell occurs in the second division of meiosis, but in the first division of mitosis. haploid gametes are produced that are all identical in their allelic composition.
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genetic variation among the daughter cells is increased.
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Binary fission is to asexual reproduction as __________ is to __________. dividing into two; genetically different offspring meiosis; mitosis mitosis; meiosis dividing into two; genetically identical offspring dividing into four; genetically different offspring
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dividing into two; genetically identical offspring
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Prokaryotic cells can divide through: binary fission. mitosis. meiosis. both mitosis and binary fission. None of the above
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binary fission.
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A part of the cytoskeleton of a cell, formed in prophase (in mitosis) or in prophase I (in meiosis), from which extend fibers that organize and separate the sister chromatids is called ________.
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spindle
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Which of the following statements about telomeres is INCORRECT? They function like a counter, keeping track of how many times a cell has divided. They are slightly shorter in prokaryotic cells than in eukaryotic cells. They function like a protective cap on chromosomes. At birth, they are long enough to permit approximately 50 cell divisions in most cells. They contain no critical genes.
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False - They are slightly shorter in prokaryotic cells than in eukaryotic cells.
