Recombinant DNA Technology Chapter 8 Exam Questions and Answers Already Passed

Recombinant DNA Technology Chapter 8 Exam Questions and Answers Already Passed What is biotechnology? - Answers The use of microorganismsto make practical products What is recombinant DNA technology? Describe the process. - Answers Technique that allows DNA to be combined from different sources; also called gene or DNA splicing. Recombinant DNA is an important technique for many gene-cloning applications. 1) Isolate plasmid: probe is used to isolate the gene of interest 2) Enzymatically cleave DNA into fragments: restriction enzyme that can locate and cut the gene from the DNA segment, cuts an opening in the recipient DNA (usually a plasmid) where the donor DNA can be attached 3) Isolate fragment w/ gene of interest: DNA ligase attaches donor and recipient DNA, forming a recombinant DNA molecule 4) Insert gene into plasmid: recombinant DNA molecule is inserted into host cell 5) Insert plasmid & gene into bacterium 6) Culture bacteria What are the three main goals of recombinant DNA technology? Give examples of each. - Answers 1) eliminate undesirable phenotypic traits in humans, animals, plants, and microbes (e.g. pest-resistant plants, cures for genetic disorders) 2) to combine beneficial traits of two or more organisms to create valuable new organisms 3) to create organisms that can synthesize products that humans need (e.g., produce vaccines, antibiotics, hormones, or enzymes) What are the 5 tools required for recombinant DNA technology? Give an example and describe the importance of each tool. - Answers 1. Mutagens: physical & chemical agents that produce mutations. Use to create changes in microbes' genomes so that the microbes phenotypes are changed 2. Reverse Transcriptase: uses RNA template to transcribe a molecule of DNA (i.e. cDNA--> RNA) 3. Synthetic nucleic acids: used as DNA probes, primers, and antisense RNAs 4. Restriction enzymes: Bacterial enzymes that cut DNA molecules only at restriction sites (usually palindromes) -Normally protect bacteria from phage by chopping up its DNA 5. Vectors: Nucleic acid molecules that deliver a gene into a cell. What are synthetic nucleic acids? Describe the 4 uses of synthetic nucleic acids? - Answers -Molecules of DNA and RNA produced in cell-free solutions (in vitro) 1. explains the genetic code: to understand genetic code & amino acid sequence of a protein 2. Create genes for specific proteins: (e.g. synthesize a gene for human insulin) 3. Synthesize DNA & RNA probes to locate specific sequences of nucleotides: using synthetic nucleic acids and radioactive chemicals (probes) for detecting genetic sequences 4. Synthesizing antisense nucleic acid molecules: antisense nucleic acid molecules control genetic diseases Why do scientists use mutations? - Answers -Change phenotypes by changing genome -Select for and culture cells w/beneficial characteristics (more potent penicillin ) -Can isolate mutated genes from the rest of the organism (easier than dealing with whole gene/cell/organism) Describe the actions of restriction enzymes and the 2 types. - Answers Restriction enzymes recognize & cut both strands of DNA molecule at a specific restriction site (usually palindromic) and produce either: a. sticky ends: staggered cuts, which only bind to complementary fragments produced by same restriction enzyme b. blunt ends: non-sticky and non-specific, which enables DNA cut by differ restriction enzymes to be combined easily. What is a genetic vector? What are the 4 useful properties that vectors share? - Answers -nucleic acid molecules such as viral genomes, transposons, & plasmids. Vectors must: 1. be small enough to manipulate in a lab 2. able to survive inside cells: plasmids make good vectors b/c they are more stable than are linear fragments of DNA, which are typically degraded by enzymes 3. contain a genetic marker: help identify the specific gene of interest, can be phenotypic markers (i.e. gene that code for antibiotic resistance) or code for enzymes that metabolize a unique nutrients, or radioactive or fluorescent labels. 4. ensure genetic expression: by providing promoters How do researchers develop vectors? Give an example. - Answers researchers are developing vectors from adenoviruses, poxviruses, and a genetically modified form of HIV. HIV might make an excellent vector b/c HIV inserts itself into human chromosomes.