Chapter 20
1. Advances in recombinant DNA technology allow scientists to work with smaller fragments of DNA, give them more tools to dissect and analyze DNA, and also allow for them to make many copies of a strand of DNA.
2. Restriction enzymes are made by bacteria to cut up invading DNA. They target specific base sequences in the DNA and then work to cut out those sequences from the DNA.
3. When a restriction enzyme cuts out a portion of DNA, it will sometimes leave a sticky end. If two fragments of DNA are cut by the same restriction enzyme, the sticky ends can join together, forming a recombinant DNA strand.
4. Cut plasmid and eukaryotic DNA with the same restriction enzyme… Mix fragments and allow them to match… Ligate… Transform into bacteria… Identify desired clone.
5. a.) The addition of a fluorescent agent can help identify a recombinant cell with a gene of interest b.) Using an AMP dish will only allow the cell carrying a gene of interest to grow
6. A genomic library contains genomic DNA sequences and represents the entire genome of the organism. A cDNA library contains sequences found in a mRNA population from a particular tissue and represents only those genes expressed in that tissue.
7. An expression vector is a plasmid that is used to introduce a specific gene into a target cell. Their goal is to produce large amounts of stable mRNA, and therefore proteins.
8. Yeast cells are easy to grow, can process pre-mRNA, and can perform post-translational modification.
9. Recombinant DNA can be introduced into eukaryotic cells by a.) Electroporation opens holes in the membrane with electricity b.) Micromanipulation with microinjection of single cells
10. PCR is a technique that basically amplifies a sequence of DNA over several orders of magnitude so that it might be detected or