Biology · 2011 · May · Paper 3 · HL · TZ1 · Question paper

Examination code 2 2 1 1 – 6 0 0 9 29 pages M11/4/BIOLO/HP3/ENG/TZ1/XX Thursday 19 May 2011 (morning) Biology HigHer level PaPer 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. 1 hour 15 minutes [Personal identifier removed] © International Baccalaureate Organization 2011 0132 2211600 9 – 2 – M11/4/BIOLO/HP3/ENG/TZ1/XX Option D — Evolution D1. Populations of threespine sticklebacks (Gasterosteus sp.), a fish living in small freshwater lakes in British Columbia, Canada, are derived from the marine threespine stickleback (Gasterosteus aculeatus). In order to investigate the process of speciation in these populations, three small lakes were studied. Each lake contained two varieties of stickleback: a large, bottom-dwelling variety that fed on invertebrates near the shore and a small, plankton-eating variety that lived in the open water. The probability of breeding between pairs of individuals was measured under laboratory conditions in the following breeding combinations: I different varieties (small × large) from the same lake II different varieties from different lakes III same variety (small × small) and (large × large) from different lakes IV same variety from the same lake. The data are summarized below. Probability of breeding 0.6 0.5 0.4 0.3 0.2 0.1 0.0 I II III IV [Source: H D Rundle, et al., (2000), Science, 287, pages 306 –308] From H. D. Rundle et al. (2000) Science, 287, pp. 306–308. Reprinted with permission from AAAS. (a) Identify the highest and lowest probabilities of breeding for individuals of the same variety from different lakes. [1] Highest probability: .................................................... Lowest probability : .................................................... (This question continues on the following page) 0232