Biology · 2014 · May · Paper 2 · SL · TZ1 · Question paper

16 pages M14/4/BIOLO/SP2/ENG/TZ1/XX Friday 9 May 2014 (afternoon) BIOLOGY STANDARD LEVEL PAPER 2 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]. 1 hour 15 minutes © International Baccalaureate Organization 2014 Examination code 2 2 1 4 – 6 0 1 1 [Personal identifier removed] [Personal identifier removed] – 2 – M14/4/BIOLO/SP2/ENG/TZ1/XX 16EP02 SECTION A Answer all questions. Write your answers in the boxes provided. 1. The mountain yellow-legged frog (Rana muscosa) was once a common inhabitant of the Sierra Nevada (California, USA). It has declined during the past century due in part to the introduction of non-native fi sh, such as trout, into naturally fi sh-free habitats. The bar chart shows the average number per lake of tadpoles (aquatic larval stage) and frogs in lakes with and without trout in 1996. Total number per lake 1000 800 600 400 200 20 15 10 5 0 Key: Lake status with trout without trout Tadpoles Frogs [Source: V . Vredenburg (2004) ‘Reversing introduced species effects: Experimental removal of introduced fi sh leads to rapid recovery of a declining frog’. PNAS, 101 (20), pp. 7646‒7650. Figure 2. Copyright 2004 National Academy of Sciences, USA.] (a) State the number of tadpoles per lake with and without trout. [1] With trout: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Without trout: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (This question continues on the following page)