Quiz 8 (Exam 2) – Flashcards
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How do we describe transformation in bacteria?
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assimilation of external DNA into a cell
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In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts?
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DNA contains phosphorus, whereas protein does not
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Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA?
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the diameter of the helix
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It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?
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sequence of bases
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In an analysis of the nucleotide composition of DNA, which of the following will be found?
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A + C = G + T
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Replication in prokaryotes differs from replication in eukaryotes for which of the following reasons?
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Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many
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What is meant by the description "antiparallel" regarding the strands that make up DNA?
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The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
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The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that
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the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose.
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The leading and the lagging strands differ in that
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the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.
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Which of the following sets of materials are required by both eukaryotes and prokaryotes for replication?
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double-stranded DNA, four kinds of dNTPs, primers, origins
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What is the function of topoisomerase?
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relieving strain in the DNA ahead of the replication fork
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Which of the following statements describes the eukaryotic chromosome?
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It consists of a single linear molecule of double-stranded DNA plus proteins
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Which of the following statements is true of histones?
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Histone H1 is not present in the nucleosome bead; instead, it draws the nucleosomes together.
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Why do histones bind tightly to DNA?
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Histones are positively charged, and DNA is negatively charged.
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Which of the following statements describes chromatin?
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Heterochromatin is highly condensed, whereas euchromatin is less compact.
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What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?
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DNA polymerase can join new nucleotides only to the 3' end of a growing strand.
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The elongation of the leading strand during DNA synthesis
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depends on the action of DNA polymerase.
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In a nucleosome, the DNA is wrapped around
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histones.
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The spontaneous loss of amino groups from adenine in DNA results in hypoxanthine, an uncommon base, opposite thymine. What combination of proteins could repair such damage?
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nuclease, DNA polymerase, DNA ligase
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In his transformation experiments, what did Griffith observe?
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Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form
