Biology · 2013 · May · Paper 3 · HL · TZ2 · Question paper

29 pages M13/4/BIOLO/HP3/ENG/TZ2/XX Tuesday 14 May 2013 (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. • A calculator is required for this paper. • The maximum mark for this examination paper is [40 marks]. 1 hour 15 minutes © International Baccalaureate Organization 2013 Examination code 2 2 1 3 – 6 0 1 5 [Personal identifier removed] 0132 2213601 5 – 2 – M13/4/BIOLO/HP3/ENG/TZ2/XX 0232 Option D — Evolution 1. Bone tools found in the Swartkrans site in South Africa were thought to be used by Australopithecus robustus when digging for food. Using replica tools, researchers dug around plants for bulbs, dug in soil for larvae and dug in termite mounds for termites. They compared the scratch marks found on the replica tools with those on the original Swartkrans tool to predict the food eaten by A. robustus. Original tool Replica tools                                      Swartkrans Plant bulbs Larvae Termites 2 mm The graphs below show the ranges of angles from the vertical position of the scratch marks and the ranges of widths of the scratch marks on each tool. The solid line on each bar represents the mean value for the range. Swartkrans Termites Larvae Plant bulbs – 40 –30 –20 –10 0 10 20 30 40 50 Angles of the scratch marks from vertical / C° Swartkrans Termites Larvae Plant bulbs 0 10 20 30 40 50 60 70 80 Widths of scratch marks / µm [Source: Lucinda R. Backwell and Francesco d’Errico, “Evidence of termite foraging by Swartkrans early hominids”, PNAS 98 (4), 1358–63. Copyright 2001, National Academy of Sciences, USA.] (This question continues on the following page)