Rättningstiden är i normalfall 15 arbetsdagar, annars är det detta datum som gäller:

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1 Molekylärbiologi Provmoment: Ladokkod: Tentamen ges för: Tentamen TK151C Bt3 7,5 högskolepoäng TentamensKod: Tentamensdatum: Tid: 14:00 18:00 Hjälpmedel: Tillåtna hjälpmedel är lexikon. Dock EJ elektroniskt lexikon Totalt antal poäng på tentamen: 71 poäng För att få respektive betyg krävs: Betyg 3: 36 poäng; Betyg 4: 46 poäng; Betyg 5: 56 poäng Allmänna anvisningar: Frågorna 8-14 besvaras på separata papper Nästkommande tentamenstillfälle: Rättningstiden är i normalfall 15 arbetsdagar, annars är det detta datum som gäller: Viktigt! Glöm inte att skriva Tentamenskod på alla blad du lämnar in. Lycka till! Ansvarig lärare: Ilona Sárvári Horváth Telefonnummer:

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3 Question 1 Which of the following statements is true about developing cdna? (2P) (a) Mature mrna directs the formation of cdna (b) Mature mrna does not contain introns (c) DNA taken from nucleus is used to produce the cdna (d) Both a and b are correct (e) None of the above are true Question 2 Bacterial DNA is not cleaved by their own restriction enzymes because bacteria add to their own DNA. (2P) (a) Nucleotides (b) Peptides (c) Methyl groups (d) Glyphosphate (e) Somatotropin Question 3 Which of the following statements are true regarding PCR (2P) (a) Billions of copies of desired DNA can be synthesized from microgram quantities of DNA (b) Automated PCR machines are called thermal cyclers (c) A thermostable DNA polymerase is required (d) All of the above Question 4 The viral genome integrated to the bacterial genome is called (2P) (a) Virion (b) Plasmid (c) Prophage (d) Capsid Question 5 Caesium chloride density gradient centrifugation to separate macromolecules depends on their (2P) (a) Molecular weight (b) Buoyant density (c) Size and charge (d) None of the above 3

4 Question 6 A library of DNA fragments results from (2P) (a) Restriction endonuclease (b) Virus (c) Plasmids (d) Recombinant DNA (e) DNA ligase Question 7 An expression vector is (2P) (a) A vector that can replicate in cells of more than one type of microorganism (b) Generally a plasmid that is used to introduce a specific gene into a target cell (c) A plasmid which can be integrated into the genome of the host cell (d) None of the above Question 8 Shown here is the plasmid RP4 which carries genes for resistance to ampicillin, tetracycline and kanamycin. How antibiotic resistance is used as a selectable marker to ensure that bacteria in a culture contains plasmid RP4? Explain with reference to Tetracycline resistance. (8P) Question 9 We have a lab culture of bacteria E. coli to be used further in cloning experiment. (a) What are the two typical media which can be used for the growth of E. coli culture for further DNA purification? How are they different based on their components (4P) (b) What are the basic steps in preparation of total cell DNA? How is it different from pure plasmid DNA purification? (6P) Question 10 Direct selection and Clone identification are the two basic strategies for obtaining the desired clone. Discuss these strategies and mention the stage at which selection occurs in them. (8P) 4

5 Question 11 Example of a linker is: GTACAGATCTCGCC CATGTCTAGAGCGG Recognition sites for few restriction enzymes EcoRI: G^AATTC BamHI: G^GATCC BglII: A^GATCT HaeIII: GG^CC How can the given linker be used to ligate a blunt ended DNA molecule? Which restriction enzyme and/or other enzyme will be used in the process? Motivate each step with a simple diagram. (9P) Question 12 What is the purpose of Polymerase Chain Reaction (PCR)? Should a primer be complimentary or identical to its template strand in order for hybridization to occur? What are the three basic steps in PCR and specific temperature range for them, also mention the specific polymerase enzyme commonly used in process. (10P) Question 13 Explain the origin of a λ-vector. How it is constructed? (4P) Question 14 Explain how a typical cosmid look like and the way it is used (8P) 5