Biology · 2012 · May · Paper 3 · SL · TZ1 · Question paper

31 pages M12/4/BIOLO/SP3/ENG/TZ1/XX Friday 18 May 2012 (morning) Biology STANDARD level PAPe R 3 INSTRUCTIONS TO CANDIDATES • Write your session number in the boxes above. • Do not open this examination paper until instructed to do so. • Answer all of the questions from two of the Options. • Write your answers in the boxes provided. • A calculator is required for this paper. • The maximum mark for this examination paper is [36 marks]. 1 hour © International Baccalaureate Organization 2012 [Personal identifier removed] Examination code 2 2 1 2 – 6 0 1 2 2 2 1 2 6 0 12 0 1 3 2 – 2 – M12/4/BIOLO/SP3/ENG/TZ1/XX Option A — Human nutrition and health A1. Iron, folic acid and vitamin B12 (cyanocobalamin) are important components of a healthy diet. These nutrients are necessary for the production of the red blood cells in the body that transport oxygen to the tissues. Deficiency of any of these nutrients can lead to anemia, a condition that causes weakness, tiredness and shortness of breath. In a study of the Piaroa, a population living in a remote area of V enezuela, investigators discovered very high levels of anemia, especially amongst young children and females of childbearing age. The table below shows the incidence of anemia and deficiencies of iron, folic acid and vitamin B12 in this population, as a percentage. Sex and age / years Anemia / % Iron deficiency / % Folic acid deficiency / % Vitamin B12 deficiency / % Female 1–3 100 56 75 0 4–10 100 31 50 10 11–20 90 55 90 20 21– 40 94 41 80 5 41+ 80 33 38 0 Mean 93 43 67 7 Male 1–3 100 50 75 25 4–10 91 36 50 0 11–20 83 25 88 22 21– 40 65 26 100 9 41+ 90 18 57 33 Mean 86 31 74 18 Overall mean 90 37 70 12 [Source: adapted from M García-Casal, et al., (2009), Archivos Latinoamericanos de Nutrición, www.alanrevista.org] (This question continues on the following page) 0 2 3 2