Microbiology HW Ch. 9 – Flashcards
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What is the end goal of PCR?
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To quickly increase the number of copies of a specific DNA sequence
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PCR stands for
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polymerase chain reaction.
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Which of the following is an application that uses PCR?
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Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
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What is the function of the primers in PCR?
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They provide a 3' end for the DNA polymerase.
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In which direction does DNA polymerase synthesize the new DNA strand?
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5' to 3'
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What provides the energy for DNA polymerization in a PCR reaction?
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Deoxyribonucleoside triphosphates
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Why is DNA polymerase from Thermus aquaticus ideal for PCR?
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It can withstand the high temperatures associated with PCR.
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How do the strands separate during PCR?
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The high heat of the denaturation step breaks the hydrogen bonds between the two strands.
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What is a thermocycler?
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The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
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What is the sequence of the temperatures of a typical PCR reaction?
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94 °C, 60 °C, 72 °C`
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How do restriction enzymes cut DNA sequences?
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They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
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In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?
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In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?
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DNA ligase
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attaches the target gene to a desired location
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Why would a recombinant DNA molecule be inserted into a host cell?
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It can be copied, transcribed, and translated into a desired protein.
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statement best describes restriction enzymes
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They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences
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Which of the following is NOT a property of useful vectors?
- They always contain only one gene.
- They must have properties that allow their survival in the host cell.
- They must be able to self-replicate.
- They must be small enough to allow them to be manipulated prior to injection.
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They always contain only one gene.
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Which of the following pairings of recombinant DNA techniques and applications does NOT match?
-genetic modification of yeast: production of purified insulin
- PCR: making many copies of a segment of DNA
- gene therapy: replacing a defective gene
- gene silencing: production of subunit vaccines
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gene silencing: production of subunit vaccines
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Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane?
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electroporation
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Why is baker's yeast useful for expressing genetically engineered genes?
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Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.
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Which of the following methods could be used to identify the source of an outbreak?
- DNA fingerprinting
- artificial selection
- reverse genetics
- production of a recombinant protein
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DNA fingerprinting
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Which of the following statements about recombinant DNA technology is FALSE?
-It allows researchers to make protein products of a gene.
- It has limited application because genes of interest cannot be moved from one type of cell to another.
- It can be used to screen individuals for many different types of genetic diseases.
- It allows researchers to make many copies of a gene of interest.
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It has limited application because genes of interest cannot be moved from one type of cell to another.
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Which of the following applications of recombinant DNA technology is NOT controversial?
-genetic food modification
- biological weapons development
- metagenomics
- genetic screening
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metagenomics
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Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium (!). Which of the following represents the correct sequence of procedures that you would use?
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1. Amplify the gene using PCR.
2. Insert the gene into a plasmid vector.
3. Transform the vector into the bacteria.
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Which statement regarding agricultural biotechnology is FALSE?
-Scientists have used gene silencing to create tomatoes with a longer shelf life.
- Scientists have created plants that are resistant to herbicides by using a mutant enzyme gene from Salmonella.
- Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.
- Scientists have created plants that produce an insect toxin originally found in bacteria.
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Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.
