UNIVERSITY OF YORK. BA, BSc, and MSc Degree Examinations Department : BIOLOGY. Title of Exam: Plant Biotechnology. Time Allowed: 2 hours

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1 Examination Candidate Number: Desk Number: UNIVERSITY OF YORK BA, BSc, and MSc Degree Examinations Department : BIOLOGY Title of Exam: Plant Biotechnology Time Allowed: 2 hours Marking Scheme: Total marks available for this paper: 100 Sec on A: Short Answer / Problem / Experimental Design ques ons (50 marks) Sec on B: Essay ques on (marked out of 100, weighted 50 marks) The marks available for each ques on are indicated on the paper Instructions: Sec on A: Answer all ques ons in the spaces provided on the examina on paper Sec on B: Answer either ques on A or ques on B. Write your answer on the separate paper provided and a ach it to the back of the ques on paper using the treasury tag provided. For marker use only: Materials Supplied: CALCULATOR Office use only: Module Total as % DO NOT WRITE ON THIS BOOKLET BEFORE THE EXAM BEGINS DO NOT TURN OVER THIS PAGE UNTIL INSTRUCTED TO DO SO BY AN INVIGILATOR page 1 of 9

2 SECTION A: Short Answer / Problem / Experimental Design questions Answer all questions in the spaces provided Mark total for this section: Below is a binary vector designed for Agrobacterium mediated transformation of tobacco. a) What important component is missing from this design? Where would you position it to ensure efficient transformation and why? (3 marks) b) Describe the method you would use to transform the plants. (3 marks) c) Briefly describe how you could find and use a tissue-specific enhancer trap line to express your transgene only in the roots. (3 marks) page 2 of 9

3 d) Briefly describe how you might ensure removal of unwanted foreign DNA from your transgenic plants in order to reduce the risk of horizontal gene transfer? (3 marks) 2. Shi et al. (2003) generated two independent transgenic Arabidopsis lines (ST-4 and ST-8) carrying the 35S:SOS1 (antiporter) transgene. They tested these lines in the presence of different concentrations of salt, measured their growth and analysed the level of SOS1 transcripts using RNA gel blot analysis. a) What result(s) would you expect from the growth experiment? Provide an explanation for your answer. The figure below shows the actual results obtained from the RNA gel blot. page 3 of 9

4 b) Interpret the results and briefly discuss any unexpected findings. (4 marks) 3. a) Give two aspects that distinguish systemic acquired resistance (SAR) from the hypersensitive response. b) Give two strategies that exploit SAR to increase disease resistance in plants. c) Discuss two advantages of exploiting SAR in manipulating disease resistance. Do not write below this line, question four on next page page 4 of 9

5 4. In plant biotechnology, an understanding of the evolutionary relationships of genes in crop and model species is important. The drawing below represents the ancestral relationships between members of a gene family involved in glucosinolate transport. a) Which gene(s) are orthologue(s) of the gene Br.GTR1a and explain why? b) Which gene(s) are paralogue(s) of the gene BoGTR1b and explain why? c) In what circumstance would the genes Br.GTR1a and Bo.GTR1a be considered homoeologues? page 5 of 9

6 5. a) Polyploid crops tend to exhibit low genetic diversity. Why is this? b) Describe the approach for broadening genetic diversity termed alien introgression, explain briefly why it is used and give two examples of its use with the polyploid crop species Brassica napus. (4 marks) 6. Cell wall extensibility is important in plant development and function. Explain the distinction between plastic and elastic extension and how each of them is important for plant development. Explain the roles of pectins and xyloglucans in determining these properties. (7 marks) page 6 of 9

7 7. Artemisinin is a natural product enriched in the glandular trichomes of Artemisia annua, and is the active ingredient in the most effective treatment for malaria. Developing plants that accumulate higher concentrations of Artemisinin (or related metabolites) in their trichomes is one important way to increase the yield of antimalarials produced by A. annua. a) What additional traits of A. annua would be suitable targets for breeding plants with improved Artemisinin yields? (3 marks) b) Give an example of a reverse genetic approach that could be used to determine the function of genes involved in the synthesis of Artemisinin. (1 mark) c) The figure below shows the relative abundance of a range of selected metabolites in chloroform extracts of A. annua leaves harvested at different stages of development. page 7 of 9

8 What can you deduce about the biosynthesis of Artemisinin from the relative abundances of these metabolites? (3 marks) Do not write below this line, Section B question on next page. page 8 of 9

9 SECTION B: Essay question Answer one question on the separate paper provided Remember to write your candidate number at the top of the page and indicate whether you have answered question A or B Mark total for this section: 50 EITHER A) You have a rice 'diversity panel' that contains several hundred rice cultivars and that is genotyped by 700,000 SNPs. Discuss how you would use this resource in a GWAS study to identify genes that are relevant to drought tolerance and what strategies you would employ to exploit this knowledge in terms of developing rice with improved drought tolerance. OR B) The manufacture of more environmentally-friendly and sustainable industrial oils may be possible through the development of elite oilseed crop varieties that can produce plant-based analogues. Discuss the merits and practicalities of different plant biotechnology approaches that could be used to develop such crops, including their implications for safety, public acceptance and regulation. page 9 of 9