D. I, II and III (Total 1 mark) 2. What is a potential consequence of the rise in global temperatures on the Arctic ecosystem?

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1 1. Which of the following are greenhouse gases? I. Oxides of nitrogen II. III. Carbon dioxide Methane A. I and II only B. I and III only C. II and III only D. I, II and III 2. What is a potential consequence of the rise in global temperatures on the Arctic ecosystem? A. Increased exposure to UV light B. Increased rate of decomposition of detritus C. Decreased success of pest species D. Increase in the ice habitat available to polar bears IB Questionbank Biology 1

2 3. The graph below shows variation in the concentration of CO 2 in the atmosphere as measured at Mauna Loa in Hawai i. The small inset graph shows the variations in CO 2 during a one year period. [Source: adapted from Dr P Tans, NOAA Earth System Research Laboratory] Why does the amount of CO 2 fall between April and August? A. Seasonal increase in the rate of photosynthesis in the northern hemisphere forests B. Seasonal decrease in the rate of photosynthesis in the northern hemisphere forests C. Seasonal decrease in the rate of fossil fuel consumption D. Seasonal increase in the amount of CO 2 dissolved in the oceans IB Questionbank Biology 2

3 4. Global warming threatens the survival of Arctic foxes. Which of the following factors could be involved? I. Competition with other fox species spreading north II. III. A. I only B. I and II only C. II and III only Reduction in numbers of prey species of Arctic foxes Decrease in oxygen availability to Arctic foxes D. I, II and III 5. Several greenhouse gases occur in the atmosphere. Carbon dioxide (CO 2 ) is one of them but so are methane (CH 4 ) and oxides of nitrogen (NO x ). Why are oxides of nitrogen classed as greenhouse gases? A. They trap some of the long-wave radiation emitted by the Earth s surface. B. They prevent short-wave radiation from reaching the Earth s surface. C. They dissolve in rainwater to produce acid rain. D. They are only produced by human activity whereas CO 2 and CH 4 are also produced naturally. IB Questionbank Biology 3

4 6. A colony of a marine diving bird, Brunnich s guillemot (Uria lomvia), lives on the southern limits of the Arctic on Coats Island. Brunnich s guillemots feed principally on Arctic cod (Arctogadus glacialis) which are characteristic of Arctic waters. The graph shows the changes in ice cover on Coats Island over a period of 19 years. [Source: Gaston, A et al Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich s guillemot (Uria lomvia L.). Journal of Animal Ecology. Vol 74. Pp Reproduced with permission from Wiley.] (a) (i) Outline the changes in ice cover shown in the data above. (i) ice cover has decreased (slightly); the data show much variability/fluctuates; (2) (ii) Suggest one reason for the changes in ice cover. warmer air/atmosphere/water temperatures/global warming (bringing about more ice melt) (1) IB Questionbank Biology 4

5 At Coats Island, chick mass at 14 days was measured in most years between 1988 and The scattergraph below shows the results, plotted against proportion of ice cover. [Source: Gaston, A et al Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich s guillemot (Uria lomvia L.). Journal of Animal Ecology. Vol 74. Pp Reproduced with permission from Wiley.] (b) (i) Outline the relationship between ice cover and the mass of 14-day-old chicks on Coats Island. increase in summer ice cover has a positive effect on mass increase; high proportion of ice cover has little effect / (slightly) negative effect on chick mass/growth; (2) (ii) Suggest reasons for the relationship. changes in (water) temperature/climate change influence fish populations / food available for chick growth; changes in habitat affect chick growth / rearing of chicks; (2) IB Questionbank Biology 5

6 (c) Predict, with a reason, the change in the mass of chicks in the years ahead. mass may go down as proportion of ice cover has decreased; mass may increase as most recent data shown in (bar) graph shows increasing proportion of ice area; (1) (Total 8 marks) IB Questionbank Biology 6