1.
If humans become infected with the Ebola virus it can have devastating effects. Strong, but not
certain, evidence suggests that trading in animal products is the main reason for the spread of the
Ebola virus to humans. Which statement about the precautionary principle is correct?
A.
In the absence of certainty about cause and effect, people should not be asked to stop
trading in animal products.
B.
The burden of proof regarding a cause and effect relationship lies with scientists.
C.
Because it is a probable cause, trading in animal products should be banned because of the
potentially devastating consequences.
D.
The precautionary principle is not relevant in this case.
(Total 1 mark)
2.
Which group of organisms in the carbon cycle converts carbon into a form that is available to
primary consumers?
A.
Decomposers
B.
Saprotrophs
C.
Detritus feeders
D.
Producers
(Total 1 mark)
3.
Which of the following are greenhouse gases?
I.
Oxides of nitrogen
II.
Carbon dioxide
III.
Methane
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
IB Questionbank Biology
1
4.
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
(Total 1 mark)
5.
Which gas will enhance the greenhouse effect if released into the atmosphere?
A.
Hydrogen
B.
Oxide of nitrogen
C.
Oxygen
D.
Nitrogen
(Total 1 mark)
6.
Which of the following is a consequence of global temperature rise on arctic ecosystems?
A.
Increased rates of decomposition of detritus trapped in permafrost
B.
Decrease of geographical range of habitats for temperate species
C.
Decrease of pest species and increase of permafrost species
D.
Increase of geographical range of habitats for permafrost species
(Total 1 mark)
IB Questionbank Biology
2
7.
Several greenhouse gases occur in the atmosphere. Carbon dioxide (CO2) is one of them but so
are methane (CH4) and oxides of nitrogen (NOx).
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 CO2 and CH4 are also produced
naturally.
(Total 1 mark)
IB Questionbank Biology
3
8.
The graph below shows variation in the concentration of CO2 in the atmosphere as measured at
Mauna Loa in Hawai’i. The small inset graph shows the variations in CO2 during a one year
period.
[Source: adapted from Dr P Tans, NOAA Earth System Research Laboratory]
Why does the amount of CO2 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 CO2 dissolved in the oceans
(Total 1 mark)
IB Questionbank Biology
4
9.
The graph below shows variation in the concentration of CO2 in the atmosphere as measured at
Mauna Loa in Hawai’i. The small inset graph shows the variations in CO2 during a one year
period.
[Source: adapted from Dr P Tans, NOAA Earth System Research Laboratory]
Why does the amount of CO2 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 CO2 dissolved in the oceans
(Total 1 mark)
IB Questionbank Biology
5
10.
The diagram below shows some of the links in the carbon cycle.
What processes are taking place at I, II and III?
I
II
III
A.
photosynthesis
fossilization
combustion
B.
cell respiration
fossilization
greenhouse effect
C.
photosynthesis
decomposition
combustion
D.
cell respiration
decomposition
greenhouse effect
(Total 1 mark)
IB Questionbank Biology
6
11.
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.
Reduction in numbers of prey species of Arctic foxes
III.
Decrease in oxygen availability to Arctic foxes
A.
I only
B.
I and II only
C.
II and III only
D.
I, II and III
(Total 1 mark)
12.
According to the precautionary principle, what should happen if there are fears that eating a food
might cause a health problem?
A.
People should be warned about the possible health problem.
B.
The company producing the food should be warned about the possible health problem.
C.
People who have fears about the food should test it to see if it causes a real health problem.
D.
The company producing the food should test the food to prove that it does not cause a
health problem.
(Total 1 mark)
IB Questionbank Biology
7
13.
Below is a graph of atmospheric CO2 levels measured at Mauna Loa Observatory, Hawai’i.
[Source: adapted from Dr P Tans, NOAA Earth System Research Laboratory]
(a)
Explain the observed changes in atmospheric CO2 concentration from 1960 to 2005.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(b)
Outline the precautionary principle.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 5 marks)
14.
Limpets are small animals that feed on the green algae which grow on rocks on seashores.
Oystercatchers (Haematopus bachmani) are birds that feed on limpets.
IB Questionbank Biology
8
In a study on the north-west coast of the USA, where three limpet species are common (Lottia
digitalis, Lottia pelta and Lottia strigatella), the limpets were protected from the oystercatchers
by large wire cages. After two years the number of limpets in this area was compared with the
number of limpets in an area without cages, where oystercatchers were present.
[Source: Wooton, J T. 1992. “Indirect effects, prey susceptibility, and habitat selection: impacts of birds on limpets and
algae”. Ecology. Vol 73. Pp 981–991. Copyright by the Ecological Society of America.]
(a)
State the effect that the exclusion of the oystercatchers had on the total number of limpets
per m2.
......................................................................................................................................
......................................................................................................................................
(1)
IB Questionbank Biology
9
(b)
Construct a food web to show the feeding relationship between the three species of limpets,
the oystercatchers and the green algae.
(2)
(c)
Suggest reasons for the difference in numbers of L. strigatella between the areas where
oystercatchers were present and where oystercatchers were excluded.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
IB Questionbank Biology
10
There is evidence to show that both air and water temperatures have increased over a period of
time. An investigation was undertaken to determine the effect this change in climate had on the
populations of another species of limpet, Patella depressa, around south-west England.
The population of the limpet was recorded in many locations and around 30 years later, this study
was repeated. The chart below compares the population in each of the locations.
[Source: Burrows, M T et al. 2009. “Predicting the effects of marine climate change on the invertebrate prey of the birds
of rocky shores: Predicting effects of climate change on invertebrates”. IBIS (Special Edition). Vol 145. Pp 40–47.]
(d)
On the map above label one location,
(i)
with the letter X, where the limpet population was abundant in the 1950s and
occasional in the 1980s (1980–1984).
(1)
(ii)
with the letter Y, where the limpet population was abundant in both the 1950s and in
the 1980s (1980–1984).
(1)
(e)
Outline, using the data, the overall trend in the limpet population from the 1950s to the
1980s (1980–1984).
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
IB Questionbank Biology
11
(f)
Suggest two reasons for the change in limpet population between the 1950s and the 1980s
(1980–1984).
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 12 marks)
15.
Up to two additional marks are available for the construction of your answers.
(2)
(a)
Living organisms at every trophic level are part of the carbon cycle. Draw a labelled
diagram of the carbon cycle to show the processes involved.
(9)
(b)
Explain, using an example of a food chain, how trophic levels can be deduced.
(4)
(c)
Explain methods that can be used to measure the rate of photosynthesis.
(5)
(Total 20 marks)
16.
Up to two additional marks are available for the construction of your answers.
(2)
(a)
Describe what is meant by a food chain using an example with four named organisms.
(4)
(b)
Outline how global warming may affect arctic ecosystems.
(5)
(c)
Explain how natural selection can lead to evolution using antibiotic resistance in bacteria as
an example.
(9)
(Total 20 marks)
17.
Up to two additional marks are available for the construction of your answers.
(2)
IB Questionbank Biology
12
(a)
Draw a labelled graph showing a sigmoid (S-shaped) population growth curve.
(4)
(b)
Describe what is meant by a food chain and a food web.
(6)
(c)
Explain the relationship between rises in concentration of atmospheric gases and the
enhanced greenhouse effect.
(8)
(Total 20 marks)
18.
Up to two additional marks are available for the construction of your answers.
(2)
(a)
Draw a labelled diagram showing the ultrastructure of a typical prokaryote.
(4)
(b)
Outline how three different environmental conditions can affect the rate of photosynthesis
in plants.
(6)
(c)
Explain how the emission of gases, both naturally and through human activity, can alter the
surface temperature of the Earth.
(8)
(Total 20 marks)
19.
Up to two additional marks are available for the construction of your answers.
(2)
(a)
Draw a labelled graph showing a typical sigmoid growth curve.
(4)
(b)
Outline the consequences of an increased greenhouse effect on arctic ecosystems.
(6)
(c)
Explain how natural selection leads to evolution.
(8)
(Total 20 marks)
20.
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.
IB Questionbank Biology
13
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.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
IB Questionbank Biology
14
(ii)
Suggest two reasons for the relationship.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(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.
......................................................................................................................................
......................................................................................................................................
(1)
IB Questionbank Biology
15
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.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
IB Questionbank Biology
16
(ii)
Suggest two reasons for the trends that you have described.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(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.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(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.
...........................................................................................................................
...........................................................................................................................
(1)
IB Questionbank Biology
17
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.
...........................................................................................................................
(1)
(ii)
State the highest temperature shown on the graph.
...........................................................................................................................
(1)
(f)
Using the data in the graph, deduce the relationship between atmospheric carbon dioxide
concentration and temperature.
......................................................................................................................................
......................................................................................................................................
(1)
IB Questionbank Biology
18
(g)
Using the data in this question, explain reasons for concern about the long-term survival of
Antarctic species, such as Laternula elliptica.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(Total 18 marks)
21.
Methane produced by anaerobic bacteria contributes substantially to atmospheric methane
concentration. These bacteria are found in a variety of habitats. Some live inside the cytoplasm of
larger unicellular organisms and are known as endosymbionts. In marine sediments,
endosymbionts living in the cytoplasm of a group of unicellular organisms, known as ciliates, can
contribute up to 90% of methane production.
To see if endosymbionts in freshwater sediments had the same effect on methane production a
one-year study was carried out in Holland. The graph below shows the rate of methane production
by untreated sediment samples and sediment samples treated to kill the ciliates containing
endosymbionts. The standard deviations are indicated by bars. The total number of ciliates is also
indicated by circles.
150
3
100
2
50
1
0
O
N
D
J
F
M
A
Time / months
M
J
J
A
S
Rate of methane production /
mol methane g–1 h–1
Ciliate numbers / ml sediment
key:
untreated
treated
0
[Source: AHAM van Hoek, et al., Acta Protozoologica, (2006), 45, pages 215–224]
IB Questionbank Biology
19
(a)
State what the standard deviation indicates.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
State the maximum number of ciliates and the month in which the maximum occurs.
.....................................................................................................................................
(1)
(c)
Compare the methane production in the untreated and treated samples.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(d)
Deduce, with reasons, whether the endosymbionts in the ciliates are responsible for the
methane produced by the sediment samples.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
IB Questionbank Biology
20
(e)
Explain how methane and other greenhouse gases cause global warming.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
Models predict global warming will cause sea temperatures to rise by approximately 2C by
2100. An investigation was carried out to study the effect of slight increases in temperature on the
ability of Antarctic marine molluscs to carry out basic activities essential for survival.
The graph below shows the effect of temperature on the percentage of limpets (Nacella concinna)
able to right themselves after being turned over.
100
% righting in 24hrs
80
60
40
20
0
0
1
2
3
4
Temperature / ºC
5
6
[Source: LS Peck, Frontiers in Zoology, (2005), 2:9]
(f)
Outline what the two parts of the scientific name Nacella concinna refer to.
.....................................................................................................................................
.....................................................................................................................................
(1)
IB Questionbank Biology
21
(g)
State the relationship between temperature and the percentage righting in N. concinna.
.....................................................................................................................................
.....................................................................................................................................
(1)
(h)
Estimate the percentage change of N. concinna able to right themselves when the
temperature is raised from 0C to 2.5C.
.....................................................................................................................................
.....................................................................................................................................
(1)
(i)
At present, the maximum summer temperature in the normal Antarctic environment of this
organism is 1C. Suggest what might be the effect on the survival of this organism if the
predicted rise in sea temperature due to global warming occurs.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 13 marks)
IB Questionbank Biology
22