Biology- Chap. 9.1 manipulating DNA – Flashcards
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Name a few of the tools that have allowed advances in genetics research
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Chemicals, computers and bacteria
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Artificial nucleotides are used to
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sequence genes
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Artificial copies of the gene are used to
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study gene expression
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Why did scientists have to find a way to get much smaller pieces of DNA?
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A whole chromosome is too large for scientists to study a particular gene easily
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What happens in gel electrophoresis?
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an electrical current is used to separate a mixture of DNA fragments from each other by size
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What are restrictive enzymes?
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enzymes that cut DNA molecules at specific nucleotide sequences --act like molecular "scissors" -come from various types of bacteria
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What is the nucleotide sequence at which restriction enzyme cuts DNA called?
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restriction site
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Why would different restriction enzymes cut the same DNA molecule into different numbers of fragments?
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Each restriction enzyme cuts DNA at a different restriction site.
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Some restriction enzymes cut straight across a DNA molecule, leaving what?
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blunt ends
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Some restriction enzymes make staggered cuts through a DNA molecule, producing...
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sticky ends
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as DNA fragments travel through a gel towards a positively charged pole, what happens?
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there are pores in the gelthat slow down larger fragments. Consequently smaller fragments travel farther than larger fragments in the same amount of time.
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what is a restriction map?
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the pattern of DNA fragments that shows up on the gel-which shows the sizes of DNA fragments between restriction sites
