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12 Cards in this Set
- Front
- Back
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Give 2 advantages of in vitro gene cloning |
• Extremely rapid • Doesn't require living cells |
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Give 3 advantages of in vivo gene cloning |
• Useful to introduce a gene into another organism • Involves almost no risk of contamination • Very accurate • Cuts out specific genes • Produces transformed bacteria that can be used to produce large quantities of gene products |
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What are the three stages of the Polymerase Chain Reaction? |
1. Separation of the DNA strand 2. Annealing of primers 3. Synthesis of DNA |
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What is a primer? |
Short sequences of nucleotides that have a set of bases complementary to those at one end of each of the two DNA strands in PCR |
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What is a thermocycler? |
A computer-controlled machine that varies the temperatures precisely over a period of time. |
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What are DNA bases which are non-coding known as? |
Variable number tandem repeats (VNTRs) |
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What does VNTR stand for? |
Variable number tandem repeats |
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What is different about each individuals VNTRs? |
The number and length has a unique pattern |
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What is gel electrophoresis used for? |
Separating DNA fragments according to their size |
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Descibe how gel electrophoresis works |
• DNA fragments placed on an agar gel and a voltage is applied across it • Larger fragments move along the gel slower than smaller fragments due to resistance of the gel • This leads to DNA fragments of different lengths being separated |
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How can the location of DNA fragments in gel electrophoresis be identified? |
• Label DNA fragments before with a radioactive probe • Place a sheet of Xray film over the agar gel for several hours • The radioactivity from each DNA fragment exposes the film and shows the location of each fragment on the gel |
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What is a limitation of gel electrophoresis? How can it be minimised? |
• Only DNA fragments up to around 500 bases long can be sequenced by gel electrophoresis • Larger genes and whole genomes can be cut into smaller fragments by restriction endonucleases beforehand |
