Half term data analysis questions
February 2015
1.	Tufted ducks (Aythya fuligula) are found in lakes and lagoons throughout Europe. They eat molluscs, insects and plants, sometimes from the surface but mostly by diving under the water. The graph shows how the heart rate of a tufted duck changes when diving under the water.

	[R Stephenson, P J Butler and A J Woakes. 1986. “Diving behaviour and heart rate in tufted ducks (Aythya fuligula).” J Exp Biol. Vol 126. Pp 341–359.]
 
(a)	State the length of time the tufted duck was under the water.
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(b)	Outline the changes in the heart rate during the dive.
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(c)	Suggest, with a reason, the type of respiration used by the tufted duck during the dive.
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	When swimming on the surface, the blood supply to different parts of the body of the tufted duck varies according to whether it is swimming at normal speed or maximum speed.

	[Source: Butler, PJ, Turner, DL, Al-Wassia, A & Bevan, RM. 1988. “Regional distribution of blood flow during swimming in the tufted duck (Aythya fuligula).” J Exp Biol. Vol 135. Pp 461–472.]
 
(d)	Calculate the percentage increase in blood flow to the leg muscles when the tufted duck changes from swimming at normal speed to swimming at maximum speed.

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(e)	Compare the blood flow to the heart muscles with the blood flow to the flight muscles when changing from swimming at normal speed to swimming at maximum speed.
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(f)	Explain the changes in blood flow that occur when swimming at maximum speed.
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(g)	Predict, with reference to both graphs, what would happen to the blood flow to the heart muscles when the tufted duck is diving.
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 (h)	State the hormone that affects heart rate.
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(Total 12 marks)

2.	Competition between genetically similar species of birds may lead to changes of one or more characteristics. One characteristic that results from this kind of selection is differences in the beaks. Researchers studied the beak lengths of two species of warblers. The graphs below show the beak lengths of Pine Warblers (Dendroica pinus) and Yellow-throated Warblers (Dendroica dominica) from three geographically isolated areas in the USA.

	[Source: R Ficken et al. 1968. Evolution. Vol 27. Pp 307–314. Republished with the permission of Wiley-Blackwell.]
 
(a)	(i)	Identify the species with the shortest mean beak length.
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(ii)	Determine the difference in the mean beak length of the two populations of Yellow-throated Warblers in Midwest and Delmarva.
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(iii)	Compare the range of variation in beak length of the Yellow-throated Warblers in Midwest to the beak length of the Yellow-throated Warblers in Delmarva.
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 (b)	Suggest an advantage for the longer beaks of Yellow-throated Warblers in Delmarva.
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(c)	Using the Yellow-throated Warbler as an example, outline the concept of allopatric speciation.
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(Total 7 marks)
3.	The effect of social stimulation on the reproductive patterns of egg-laying female Zebra finches (Taeniopygia guttata) was studied. The sounds of the same colony (intra-colony) and of a different colony (extra-colony) were recorded and played to different pairs of Zebra finches.
	Graph A shows the mean time until the laying of the first eggs. Graph B shows the mean clutch size (total number of eggs per pair). The control pairs had no recordings played to them.

	[Source: J Waas et al. 2005. Proceedings of the Royal Society. Vol 272. Pp 383–388. Reproduced with permission.]
(a)	Identify the mean time until the laying of the first eggs in the control group of Zebra finches.
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(b)	Calculate the percentage decrease between the mean time until the laying of the first eggs in pairs of Zebra finches exposed to intra-colony sounds and in pairs exposed to extra-colony sounds. Show your working.

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(c)	Evaluate the effect of the recorded colony sounds on the reproductive pattern of laying eggs in Zebra finches.
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(Total 6 marks)

4.	Scientists studied the flight behaviour of bumblebees (Bombus terrestris) searching for artificial flowers of various sizes and colours. The search time is the time taken from leaving the first flower to landing on the second flower. The colour contrast is an arbitrary value which shows the colour contrast of the flowers with their green leaf-like type background.
The graph below shows the search time for flowers of different colours and sizes.

	[Spaethe, J, Tautz, J and Chittka, L. 2001. “Visual constraints in foraging bumblebees: Flower size and color affect search time and flight behaviour”. Proceedings of the National Academy of Sciences. Vol 98, issue 7. Pp 3898–3903. Copyright 2001 National Academy of Sciences, USA.]
 
(a)	State the time it takes bumblebees to reach a blue flower of 15 mm diameter from another flower.
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(b)	State the colour of flower the bumblebees find in least time.
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(c)	Describe the effect of colour contrast on search time for the larger flowers (25 mm diameter).
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 (d)	When searching for smaller flowers, bumblebees changed the strategies used for larger flower detection. Evaluate this hypothesis using the data.
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(e)	Suggest the type of behavior shown by bumblebees in this experiment and how it can affect their chances of survival.
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(Total 7 marks)
5.	Evidence suggests that the behaviour of bees is often a response to odours. Scientists placed bees 200 cm away from an attractive odour source. An experimental group of bees had previous exposure to the odour, a control group had no previous exposure. Both the percentage of bees flying towards (orientated flight) and the percentage circling the odour source were measured.
		
	[Source: Antoine Chaffiol, David Laloi, and Minh-Hà Pham-Delègue. 2005.  “Prior classical olfactory conditioning improves odour-cued flight orientation of honey bees in a wind tunnel”. Journal of Experimental Biology. Vol 208, issue 19. Pp 3731–3737 (Figure 3). © Company of Biologists Ltd.]
 (a)	Calculate the percentage increase in orientated flight between the control group and the experimental group.
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(b)	Describe the effect of previous exposure to the odour on the flight of bees.
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 (c)	Outline the type of behaviour that the experimental group demonstrates.
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 (d)	Discuss the implications of this study for the survival of bees.
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(Total 7 marks)
6.	Circadian rhythms are daily cycles in physiology and behaviours. Cryptochromes are proteins that are thought to be involved in circadian rhythm in mammals.
Two groups of mice were identified. Group A could produce cryptochrome, Group B could not. The behaviour of the mice was assessed by monitoring wheel running activity over a 28-day period. For the first seven days the animals were given alternating 12-hour periods of light and dark. Between days 8 and 28 they were kept in continuous darkness.
The rotation of the running wheel is plotted as a dark area within the boxes, the time of day is plotted on the x-axis. The band on top indicates the dark and light periods in the first seven days.

[Source: Aziz Sancar, (August 2004), The Journal of Biological Chemistry, 279, (33), pages 34079-34082]
(a)	(i)	State the light conditions when mice were most active during the first 7 days.
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(ii)	Suggest one reason for mice showing this behaviour.
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(b)	Compare the effect of constant darkness on groups A and B.
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 (c)	Evaluate the hypothesis that cryptochromes are necessary for establishing circadian rhythms.
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(Total 7 marks)

7.	Global atmospheric carbon dioxide levels are rising. A study was carried out to test if the temperature dependence of photosynthesis was altered by elevated atmospheric CO2.
Maize plants were grown in natural sunlight in controlled environmental chambers at different temperatures using current atmospheric and doubled CO2 levels.
	The graph below shows daily patterns of CO2 exchange at three different temperatures.
Open shapes (○, Δ, □) represent current atmospheric CO2 levels and closed shapes (●, ▲, ■) represent elevated CO2 levels.
		
	[Reprinted from: Kim, S H et al. 2007. “Temperature dependence of growth, development, and photosynthesis in maize under elevated CO2”. Environmental and Experimental Botany. Vol 61. Pp 224–236.]
 (a)	(i)	State the time at which carbon dioxide exchange rate is maximal.
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(ii)	Explain the reasons for maximum carbon dioxide exchange rate at this time.
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 (b)	State the temperature that resulted in the highest rate of photosynthesis under current atmospheric conditions.
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(c)	Using the data in the graph, discuss whether rising carbon dioxide levels in the atmosphere will increase growth rates in maize.
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(Total 6 marks)
8.	Drug abuse and alcohol abuse are neurobehavioural disorders of complex origin. A human gene has been identified that encodes the main enzyme (FAAH) for inactivating cannabinoid (THC). A mutation in this gene can occur and the homozygous mutation allows normal catalytic activity of FAAH but makes the FAAH more likely to be broken down. A study was conducted to test for the presence of the homozygous FAAH mutation in relation to drug and alcohol abuse. Four different groups were formed based on their use of drugs and alcohol.

	[Adapted from Sipe, J C et al. 2002. PNAS. Pp 8394–8399. Copyright 2002 National Academy of Sciences, USA.]
 (a)	Identify the percentage of homozygotes among drug users only.
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(b)	Calculate the actual number of homozygotes in group 2.
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 (c)	Evaluate the evidence to support the hypothesis that the presence of the homozygous mutation is a risk factor in drug and alcohol use.
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(d)	Suggest a reason for the high incidence of homozygotes among drug and alcohol users.
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(Total 7 marks)

9.	Corals can be male, female or hermaphrodite (both male and female) and the release of their gametes is called spawning. Data was collected to study the spawning behaviour in the Gulf of Mexico of three genera of coral: Montastraea, Stephanocoenia and Diploria.
	The spawning behaviour is expressed in minutes post-sunset. Peak spawning windows are shown as grey bars () and the range as black bars ().

	[Source: adapted from P D Vize, J A Embesi, M Nickell, D P Brown and D K Hagman. 2005. “Tight temporal consistency of coral mass spawning at the Flower Garden Banks, Gulf of Mexico, from 1997–2003.” Gulf of Mexico Science. Vol 1. Pp 107–114. © 2005 by the Marine Environmental Sciences Consortium of Alabama.]
(a)	State the range of the time of spawning for the male M. cavernosa.
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(b)	Suggest why it may be advantageous for each species of coral to spawn within a tight time frame.
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 (c)	Discuss the significance of different spawning windows for different species.
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(d)	Scientists hypothesized that the release of the male gamete triggers a chemical signal for females to release their eggs. Discuss this hypothesis.
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(e)	The spawning window of D. strigosa is shown as a shaded gradient indicating a strong bias towards spawning in the early portion of the window. Suggest a reason for the spawning behaviour of D. strigosa.
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(f)	Define the term innate behaviour.
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(Total 8 marks)

10.	During aerobic cell respiration, oxygen is consumed and carbon dioxide is produced inside cells. This generates concentration gradients between respiring cells and the environment, which cause diffusion of oxygen and carbon dioxide. Both oxygen and carbon dioxide are soluble in water. As the temperature rises, water becomes saturated at a lower concentration of the gas.
	Laternula elliptica is a mollusc that lives on the sea bed in Antarctica. Its body temperature is always similar to that of the environment around it. To investigate the effect of temperature on Laternula elliptica, specimens were kept in temperature-controlled aquaria. The oxygen concentrations of water near the gills and in the body fluids were measured, at a range of temperatures from 0°C to 9°C. The graph below shows the mean results.
		
	[With kind permission from Springer Science+Business Media and the author.]
(a)	(i)	Outline the relationship between temperature and oxygen concentration in the body fluids in Laternula elliptica.
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(ii)	Suggest two reasons for the relationship.
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(b)	In its natural environment, Laternula elliptica buries itself in the mud on the sea bed.
In this investigation, it was found that above 6°C it is unable to bury itself. Suggest a reason for this.
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	The world’s oceans can absorb large amounts of carbon dioxide. This process has been studied in the Pacific Ocean near Hawaii, by measuring carbon dioxide concentrations in the atmosphere and in surface water every month, from October 1988 onwards. The graph below shows the carbon dioxide concentration expressed as partial pressures (Pco2).

	[Source: Nature by Nature Publishing Group. Reproduced with permission of Nature Publishing Group in the format Journal via Copyright Clearance Centre.]

(c)	(i)	Describe the trends in atmospheric carbon dioxide concentration, shown in the graph.
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(ii)	Suggest two reasons for the trends that you have described.
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(d)	(i)	Diffusion of carbon dioxide only occurs when there is a concentration gradient.
Deduce the pattern of carbon dioxide diffusion, between water and atmosphere, from 1988 to 2002.
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(ii)	The graph provides evidence for the hypothesis that there will be no net diffusion of carbon dioxide between water and atmosphere by 2020. Explain this evidence.
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	The concentration of carbon dioxide in the atmosphere is currently 385 ppm (parts per million).
Variations in the concentration of carbon dioxide in the atmosphere can be studied using ice-cores. An ice-core record covering the last 400 000 years has been obtained from Vostok in the Antarctic. The graph below shows the carbon dioxide concentrations that were measured at different depths in the ice. Atmospheric temperatures are also shown on the graph. These were deduced from ratios of oxygen isotopes. The upper line on the graph shows CO2 concentrations and the lower line shows temperature.

	[Source: Nature by Nature Publishing Group. Reproduced with permission of Nature Publishing Group in the format Journal via Copyright Clearance Centre.]
 (e)	(i)	State the highest carbon dioxide concentration shown on the graph.
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(ii)	State the highest temperature shown on the graph.
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(f)	Using the data in the graph, deduce the relationship between atmospheric carbon dioxide concentration and temperature.
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(g)	Using the data in this question, explain reasons for concern about the long-term survival of Antarctic species, such as Laternula elliptica.
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(Total 18 marks)
11.	Desert ants (Cataglyphis fortis) use odour to help find their food. When a constant wind is blowing, the ants do not approach food directly. Instead, they walk downwind of the food source and then, when they detect the odour of the food, they follow the odour trail upwind until they reach the food, as shown in the figure below.

	[Adapted with permission from Wolf, H and Wehner, R. 2005. Journal of Experimental Biology. Vol 208. Pp 4223–4230. Where appearing online or in other electronic media, a link should be provided to the original article (eg, via DOI): The Journal of Experimental Biology: jeb.biologists.org.]
	To investigate this behaviour pattern, feeders were established at distances of 5 m to 60 m away from the nest. Each feeder consisted of a Petri dish filled with biscuit crumbs. The graph below shows the distribution of downwind approach distances for each different nest-feeder distance.
		
	[Adapted with permission from Wolf, H and Wehner, R. 2005. Journal of Experimental Biology. Vol 208. Pp 4223–4230. Where appearing online or in other electronic media, a link should be provided to the original article (eg, via DOI): The Journal of Experimental Biology: jeb.biologists.org.]

(a)	Outline the relationship between the downwind approach distance and the nest-feeder distance.
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 (b)	Compare the results observed when the feeders were located at 5 m with the feeders at 60 m.
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 (c)	Suggest one possible source of uncertainties or errors in these experiments.
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(d)	Deduce, with a reason, what type of behaviour pattern is shown by the ants in the experiment.
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(Total 7 marks)

 
12.	The element arsenic (As) is not needed for plant growth and development. The accumulation of arsenic in the Chinese brake fern (Pteris vittata) was studied. Young ferns with five or six leaves were transplanted to soil contaminated with arsenic and were grown for 20 weeks in a greenhouse.
	The graph below shows the arsenic concentrations in leaves and roots of the Chinese brake fern during the 20 weeks after transplanting. Arsenic concentration is expressed as mg As kg–1 dry weight of plant.
		
	[Used with permission, from Journal of Environmental Quality. 2002. Vol 31. Pp 1671–1675.]
 (a)	Using the data in the graph, describe the accumulation of arsenic in the Chinese brake fern.
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	The table below shows the total amount of arsenic accumulated by the Chinese brake fern, expressed as a concentration in the plant tissue and as a percentage of the arsenic originally in the soil.

Time / weeks	Arsenic concentration in fern / mg As kg–1	Percentage of original soil arsenic absorbed by fern	
0	2	0.00	
2	66	0.05	
4	221	0.15	
6	408	0.28	
8	1300	0.88	
12	5390	3.68	
16	13800	9.43	
20	37900	25.90	
	[Adapted from Sinton, L W et al. 1999. Applied and Environmental Microbiology. Vol 65, issue 8. Pp 3605–3613. Published by the American Society for Microbiology, 1752 N Street N.W., Washington, DC 20036, USA. Reproduced with permission.]
(b)	(i)	Assuming the mean rate of arsenic accumulation over the first 20 weeks continued, calculate how long it would take to remove all the arsenic from the soil.
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(ii)	Using the data in the table, discuss the potential of using Chinese brake fern to remove arsenic from contaminated soil.
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(c)	Suggest one possible consequence of arsenic accumulation in plants for other organisms in the community.
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(Total 7 marks)