BIO00018I Examination Candidate Number: Desk Number: University of York Department of Biology B. Sc Stage 2 Degree Examinations 2016-17 Postgenomic Biotechnology Time allowed: 1 hour and 30 minutes Total marks available for this paper: 80 This paper has three parts: Section A: Short answer questions (30 marks) · Answer all questions in the spaces provided on the examination paper Section B: Problem questions (20 marks) · Answer all questions in the spaces provided on the examination paper Section C: Long answer question (marked out of 100, weighted 30 marks) · Answer either question A or question B or question C . Write your answer on the separate paper provided and attach it to the back of the question paper using the treasury tag provided . The marks available for each question are indicated on the paper · A calculator will be provided For marker use only: 1 2 3 4 5 6 7 8 9 10 For office use only: Total as % page 1 of 11
BIO00018I SECTION A: Short answer questions Answer all questions in the spaces provided Mark total for this section: 30 1. Outline three characteristics of a polymerase used for PCR that could be improved by molecular engineering. (3 marks) Any three of: · processivity . polymerisation rate · fidelity . ability to cope with a wider range of buffer conditions (e.g. inhibitory salt concentrations) . Other correct answers will also be marked as such LO1. demonstrate, through the use of examples, a good knowledge of a number of cutting-edge, high- and low-throughput "omics" biotechnologies Most students were able to answer this question correctly 2. a) Explain when multiple displacement amplification (MDA) would be preferable to using the polymerase chain reaction (PCR) for amplifying a DNA sample? (1 mark) When the sequence of the DNA to be amplified is unknown Students were awarded partial marks for "circular chromosomes" although PCR can also be used in this context. Low quantities of DNA was not an acceptable answer as PCR works well under these circumstances b) How do the reagents and conditions for MDA differ from those used in PCR? (6 marks) MDA is an isothermal reaction (1 mark) utilising primers that are thiophosphate-linked random hexamers (2 marks), uses phi29 DNA polymerase which has strand displacement activity (2 marks) and page 2 of 11
BIO00018I functions at 30? (1 mark) [compared to PCR which uses specific sequence oligonucleotides, a thermostable DNA polymerase that does not have strand displacement activity and requires thermal cycling.] LO3. demonstrate an understanding of the biological principles underlying these technologies by an ability to identify, and justify the use of, an appropriate biotechnology for collection of a particular sort of data Students lost marks for not providing sufficient detail in their answers 3. What by-products, released when nucleotide bases are incorporated during sequencing, are detected by pyrosequencing and ion semiconductor sequencing technologies respectively? (2 marks) The release of pyrophosphate is detected in pyrosequencing (1 mark) and the release of hydrogen ions is detected