Biology · 2017 · May · Paper 3 · SL · TZ1 · Question paper

36EP01 M17/4/BIOLO/SP3/ENG/TZ1/XX © International Baccalaureate Organization 2017 2217 – 6012 Instructions to candidates • Write your session number in the boxes above. • Do not open this examination paper until instructed to do so. • Answers must be written within the answer boxes provided. • A calculator is required for this paper. • The maximum mark for this examination paper is [35 marks]. Section A Questions Answer all questions. 1 – 3 Section B Questions Answer all of the questions from one of the options. Option A — Neurobiology and behaviour 4 – 7 Option B — Biotechnology and bioinformatics 8 – 12 Option C — Ecology and conservation 13 – 16 Option D — Human physiology 17 – 21 [Personal identifier removed] Standard level Paper 3 33 pages Tuesday 2 May 2017 (morning) 1 hour Section A Answer all questions. Write your answers in the boxes provided. 1. Urease is an enzyme that breaks down urea into ammonia and carbon dioxide. The ammonia produced causes the pH of the solution to rise. This reaction can be followed using a pH indicator or a pH probe. In an experiment conducted by a student the time taken for the pH indicator, thymol blue, to change from yellow to blue was recorded at different temperatures. Temperature / °C ± 1 Time / s ± 1 Trials Mean Standard deviation1 2 3 4 5 30 109 62 79 59 65 75 21 40 54 46 38 42 43 45 6 50 31 30 31 34 27 31 3 60 23 18 19 21 18 20 2 70 19 29 29 31 36 29 6 [Source: © International Baccalaureate Organization 2017] (a) Outline what the standard deviations reveal about the data from this experiment. [2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (b) One result in this