Biol 140: Chapter 15
31 Cards in this Set
Front | Back |
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When was the Hershey-Chase experiment conducted?
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1952
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What did the Hershey-Chase experiment seek to answer?
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Are genes comprised of DNA or proteins?
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What did the Hershey-Chase experiment determine?
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Genes are made up of DNA
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What kind of backbone does DNA have?
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Sugar-phosphate
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What attached to the backbone of DNA?
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Nitrogenous bases
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Who discovered the secondary structure of DNA?
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Watson and Crick
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When did Watson and Crick discover the secondary structure of DNA?
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1953
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What is the secondary structure of DNA?
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The double helix, with each backbone running antiparellel
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What kind of bonds occur between nitrogenous bases in DNA?
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Hydrogen bonds
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What type of replication occurs in DNA synthesis?
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Semi-conservative
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How does semi-conservative replication work?
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-Parent strands separate and act as a template
-Daughter strands attach via complimentary base pairing
-DNA polymerase adds nucleotides to DNA
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What end are nucleotides added to in semi-conservative replication?
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The exposed 3′ OH end
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What direction is DNA synthesized in?
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5′→3′
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What are the two strands in DNA replication?
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Lagging and Leading
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What does DNA helicase do?
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Breaks hydrogen bonds between base pairs
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What stabilizes the unwound DNA?
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Binding proteins
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What is DNA primase?
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Creates short RNA strands that act as primers
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What does DNA replication move towards?
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The replication fork
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Is synthesis continuous or discontinuous away from the replication?
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Discontinuous
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What is primase?
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Creates short RNA primers
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What are the short fragments in the RNA of the lagging strand called?
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Okazaki fragments
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In what direction do Okazaki fragments move?
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5′→3′
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What is DNA ligase?
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Closes the gaps between Okazaki fragments
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What creates Okazaki fragments?
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DNA polymerase
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What occurs at the end of Eukaryotic chromosomes?
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A telomere
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What are telomeres made of?
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Short, repeated bases
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What synthesizes telomeres?
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Telomerase
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What type of cells are telomeres mostly found in?
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Sex cells
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There is a correlation between telomere length and what?
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Number of cell divisions
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What is one way to increase cell division in somatic cells?
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Add telomeres
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Cancer cells have active what?
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Telomeres
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