Biology · 2015 · May · Paper 2 · SL · TZ2 · Question paper

M15/4/BIOLO/SP2/ENG/TZ2/XX Instructions to candidates • Write your session number in the boxes above. • Do not open this examination paper until instructed to do so. • Section A: answer all questions. • Section B: answer one question. • Write your answers in the boxes provided. • A calculator is required for this paper. • The maximum mark for this examination paper is [50 marks]. 20 pages © International Baccalaureate Organization 2015 Biology Standard level Paper 2 Wednesday 6 May 2015 (morning) 1 hour 15 minutes [Personal identifier removed] 20EP01 – 2 – M15/4/BIOLO/SP2/ENG/TZ2/XX 20EP02 Section A Answer all questions. Write your answers in the boxes provided. 1. Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Toledo Corozal Orange Walk Cayo Belize district Stann Creek Key: National border District border River Lowest incidence of malaria Highest incidence of malaria Note: The intermediate incidence of malaria has not been shown [Source: adapted from S. Hakre et al. (2004) International Journal of Health Geographics, 3 (6). Spatial correlations of mapped malaria rates with environmental factors in Belize, Central America. Shilpa Hakre, Penny Masuoka, Errol Vanzie and Donald R. Roberts © 2004 Hakre et al; licensee BioMed Central Ltd] (This question continues on the following page)