Topic 4: Ecology

In an area of forest measuring 100 m by 100 m, samples were taken to estimate the number of silver maple (Acer saccharinum) trees in the forest. The number of trees counted in each of five areas of 400 m² was recorded.

Approximately how many silver maple trees are in the 10000m² area of forest?

A. 5

B. 25

C. 125

D. 625

Describe the process of peat formation.

In an area of forest measuring 100 m by 100 m, samples were taken to estimate the number of silver maple (Acer saccharinum) trees in the forest. The number of trees counted in each of five areas of 400 m² was recorded.

Approximately how many silver maple trees are in the 10000m² area of forest?

A. 5

B. 25

C. 125

D. 625

Describe the process of peat formation.

Describe the process of peat formation.

The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.

The diagram shows the carbon cycle.

[Source: © International Baccalaureate Organization 2017]

Which two processes correspond to the labelled arrows?

A. K is combustion and L is catabolism.

B. J is anabolism and K is respiration.

C. J is combustion and K is respiration.

D. J is anabolism and L is catabolism.

The diagram shows the carbon cycle.

[Source: © International Baccalaureate Organization 2017]

Which two processes correspond to the labelled arrows?

A. K is combustion and L is catabolism.

B. J is anabolism and K is respiration.

C. J is combustion and K is respiration.

D. J is anabolism and L is catabolism.

The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.

The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.

Calculate the total number of M. lucifugus flights that were recorded in the summer of 2007

Calculate the total number of M. lucifugus flights that were recorded in the summer of 2007

The three-toed sloth, Bradypus variegatus, lives in tree tops where it feeds on leaves. It also feeds on algae and fungi which live in its fur.

[Source: Image from https://commons.wikimedia.org/wiki/File:Bradypus_variegatus.jpg. Christian Mehlführer.
Licensed under CC by 2.5 https://creativecommons.org/licenses/by/2.5/deed.en]

In which trophic group should the three-toed sloth be classified?

A. Autotroph

B. Consumer

C. Detritivore

D. Saprotroph

Calculate the total number of M. lucifugus flights that were recorded in the summer of 2007

Suggest one limitation of this recording method in determining the accurate mean number of individual bats flying.

The three-toed sloth, Bradypus variegatus, lives in tree tops where it feeds on leaves. It also feeds on algae and fungi which live in its fur.

[Source: Image from https://commons.wikimedia.org/wiki/File:Bradypus_variegatus.jpg. Christian Mehlführer.
Licensed under CC by 2.5 https://creativecommons.org/licenses/by/2.5/deed.en]

In which trophic group should the three-toed sloth be classified?

A. Autotroph

B. Consumer

C. Detritivore

D. Saprotroph

Suggest one limitation of this recording method in determining the accurate mean number of individual bats flying.

Suggest one limitation of this recording method in determining the accurate mean number of individual bats flying.

Calculate the percentage decline in the mean number of M. lucifugus flights for 2009 when compared to 2008.

Calculate the percentage decline in the mean number of M. lucifugus flights for 2009 when compared to 2008.

Outline how greenhouse gases interact with radiation and contribute to global warming.

Calculate the percentage decline in the mean number of M. lucifugus flights for 2009 when compared to 2008.

Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.

Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.

Outline how greenhouse gases interact with radiation and contribute to global warming.

Outline how greenhouse gases interact with radiation and contribute to global warming.

Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.

Distinguish between the patterns of hibernation of the uninfected and infected bats.

Distinguish between the patterns of hibernation of the uninfected and infected bats.

Distinguish between the patterns of hibernation of the uninfected and infected bats.

Based on the data and your biological knowledge, suggest how the infection could lead to premature death in a bat.

Based on the data and your biological knowledge, suggest how the infection could lead to premature death in a bat.

Based on the data and your biological knowledge, suggest how the infection could lead to premature death in a bat.

Outline the relationship between date of death and the mean interval between hibernation emergence periods.

Outline the relationship between date of death and the mean interval between hibernation emergence periods.

Outline the relationship between date of death and the mean interval between hibernation emergence periods.

Discuss whether the data in the graph show that there is a causal link between the date of death and the interval between hibernation emergence periods.

Discuss whether the data in the graph show that there is a causal link between the date of death and the interval between hibernation emergence periods.

Discuss whether the data in the graph show that there is a causal link between the date of death and the interval between hibernation emergence periods.

Suggest one reason, other than the interval between hibernation emergence periods, for some infected bats surviving longer than others.

Suggest one reason, other than the interval between hibernation emergence periods, for some infected bats surviving longer than others.

Suggest one reason, other than the interval between hibernation emergence periods, for some infected bats surviving longer than others.

Using all of the data, predict the effect of WNS on bat populations.

Using all of the data, predict the effect of WNS on bat populations.

Using all of the data, predict the effect of WNS on bat populations.

The image shows a food web.

[Source: Adapted from Thompsma/Wikipedia]

Which organism in the food web is assigned to its method of nutrition?

A. A violet webcap fungus is both an autotroph and a heterotroph.

B. A pillbug is a secondary consumer.

C. Bacteria are saprotrophs.

D. A violet webcap fungus is a detritivore.

Outline how chi-squared can be used to test for an association between the distributions of the two species.

Outline how chi-squared can be used to test for an association between the distributions of the two species.

Outline how chi-squared can be used to test for an association between the distributions of the two species.

The image shows a food web.

[Source: Adapted from Thompsma/Wikipedia]

Which organism in the food web is assigned to its method of nutrition?

A. A violet webcap fungus is both an autotroph and a heterotroph.

B. A pillbug is a secondary consumer.

C. Bacteria are saprotrophs.

D. A violet webcap fungus is a detritivore.

The Venus flytrap (Dionaea muscipula) is a photosynthetic plant. It obtains nitrogen but not energy by digesting captured insects.

The Venus flytrap (Dionaea muscipula) is a photosynthetic plant. It obtains nitrogen but not energy by digesting captured insects.

The Australian pitcher plant (Cephalotus follicularis) is a green plant that traps and feeds on flies and other live insects. What is this plant’s mode of nutrition?

A.  Producer and saprotroph

B.  Autotroph and detritivore

C.  Autotroph and heterotroph

D.  Consumer and saprotroph

The Australian pitcher plant (Cephalotus follicularis) is a green plant that traps and feeds on flies and other live insects. What is this plant’s mode of nutrition?

A.  Producer and saprotroph

B.  Autotroph and detritivore

C.  Autotroph and heterotroph

D.  Consumer and saprotroph

In 1789 Gilbert White, a naturalist, observed eight breeding pairs of swifts (Apus apus) in the English village of Selborne. On average, each pair of swifts produces two offspring per year. This would allow the population to rise to 1030 swifts over 200 years. A bird survey carried out in 1983 revealed only 12 breeding pairs in this village.

What could have prevented the numbers rising to 1030?

I.   The number of nesting sites remained the same.

II.  The food supply of the swifts remained constant.

III. Predatory birds in the area were exterminated.

A.  I only

B.  I and II only

C.  II and III only

D.  I, II and III

In 1789 Gilbert White, a naturalist, observed eight breeding pairs of swifts (Apus apus) in the English village of Selborne. On average, each pair of swifts produces two offspring per year. This would allow the population to rise to 1030 swifts over 200 years. A bird survey carried out in 1983 revealed only 12 breeding pairs in this village.

What could have prevented the numbers rising to 1030?

I.   The number of nesting sites remained the same.

II.  The food supply of the swifts remained constant.

III. Predatory birds in the area were exterminated.

A.  I only

B.  I and II only

C.  II and III only

D.  I, II and III

State two causes of the decrease of biomass along food chains in terrestrial ecosystems.

State two causes of the decrease of biomass along food chains in terrestrial ecosystems.

Describe how detritivores obtain nutrition and the effects they have in ecosystems.

State two causes of the decrease of biomass along food chains in terrestrial ecosystems.

The table shows the global carbon budget over two decades; the years 1990 to 1999 and 2000 to 2009.

[Source: © International Baccalaureate Organization 2019]

Using the table, explain causes of the changes in carbon flux over the two decades.

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

The table shows the global carbon budget over two decades; the years 1990 to 1999 and 2000 to 2009.

[Source: © International Baccalaureate Organization 2019]

Using the table, explain causes of the changes in carbon flux over the two decades.

The table shows the global carbon budget over two decades; the years 1990 to 1999 and 2000 to 2009.

[Source: © International Baccalaureate Organization 2019]

Using the table, explain causes of the changes in carbon flux over the two decades.

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

Describe how detritivores obtain nutrition and the effects they have in ecosystems.

Describe how detritivores obtain nutrition and the effects they have in ecosystems.

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

The Silver Springs feed into the Silver River in Florida. The diagram shows a pyramid of energy for the Silver Springs ecosystem. The units are kJ m^–2 y^–1.

[Source: © International Baccalaureate Organization 2019]

What do level I and level III represent in the pyramid of energy?

The Silver Springs feed into the Silver River in Florida. The diagram shows a pyramid of energy for the Silver Springs ecosystem. The units are kJ m^–2 y^–1.

[Source: © International Baccalaureate Organization 2019]

What do level I and level III represent in the pyramid of energy?

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

Deforestation and agricultural activities including the production of crops and livestock are thought to play a major role in the greenhouse effect. The graph shows annual trends in rates of deforestation and the production of soybeans and cattle in the state of Mato Grosso in Brazil in the period from 2001 to 2010.

[Source: 'Decoupling of deforestation and soy production in the southern Amazon during the late 2000s.'
Marcia N. Macedo, Ruth S. DeFries, Douglas C. Morton, Claudia M. Stickler, Gillian L. Galford, and Yosio E.
Shimabukuro PNAS January 24, 2012, 109 (4) 1341–1346; https://doi.org/10.1073/pnas.1111374109,
used with permission]

What conclusion can be drawn from the information in this graph?

A. The decline in rates of deforestation led to an increase in production of CO2.

B. Soybean production accounted for a greater proportion of deforestation than cattle production.

C. Forest habitats declined during the first few years of the study.

D. The decline in rates of deforestation is due to an increase in soybean production.

Deforestation and agricultural activities including the production of crops and livestock are thought to play a major role in the greenhouse effect. The graph shows annual trends in rates of deforestation and the production of soybeans and cattle in the state of Mato Grosso in Brazil in the period from 2001 to 2010.

[Source: 'Decoupling of deforestation and soy production in the southern Amazon during the late 2000s.'
Marcia N. Macedo, Ruth S. DeFries, Douglas C. Morton, Claudia M. Stickler, Gillian L. Galford, and Yosio E.
Shimabukuro PNAS January 24, 2012, 109 (4) 1341–1346; https://doi.org/10.1073/pnas.1111374109,
used with permission]

What conclusion can be drawn from the information in this graph?

A. The decline in rates of deforestation led to an increase in production of CO2.

B. Soybean production accounted for a greater proportion of deforestation than cattle production.

C. Forest habitats declined during the first few years of the study.

D. The decline in rates of deforestation is due to an increase in soybean production.

Calculate the percentage increase in the use of liquid fuels from 1950 to 1975.

%

Calculate the percentage increase in the use of liquid fuels from 1950 to 1975.

%

Calculate the percentage increase in the use of liquid fuels from 1950 to 1975.

%

Referring to the data, compare and contrast the changes in the use of the different fuels between 1950 and 1975.

Referring to the data, compare and contrast the changes in the use of the different fuels between 1950 and 1975.

Referring to the data, compare and contrast the changes in the use of the different fuels between 1950 and 1975.

Explain the movement of energy and inorganic nutrients in an ecosystem.

Explain the movement of energy and inorganic nutrients in an ecosystem.

Explain the movement of energy and inorganic nutrients in an ecosystem.

Compare and contrast the trends for O. rufipogon and O. sativa indica.

Compare and contrast the trends for O. rufipogon and O. sativa indica.

Compare and contrast the trends for O. rufipogon and O. sativa indica.

Which level(s) of ecological complexity involve(s) biotic factors but not abiotic factors?

I. Community

II. Ecosystem

III. Population

A. I only

B. II only

C. I and II only

D. I and III only

Which level(s) of ecological complexity involve(s) biotic factors but not abiotic factors?

I. Community

II. Ecosystem

III. Population

A. I only

B. II only

C. I and II only

D. I and III only

In the diagram, which of the processes labelled A to D transfers the largest mass of carbon per year in a woodland ecosystem?

[Source: © International Baccalaureate Organization 2019]

In the diagram, which of the processes labelled A to D transfers the largest mass of carbon per year in a woodland ecosystem?

[Source: © International Baccalaureate Organization 2019]

Compare and contrast the design of both mesocosms (vertical flow and horizontal flow).

Compare and contrast the design of both mesocosms (vertical flow and horizontal flow).

Compare and contrast the design of both mesocosms (vertical flow and horizontal flow).

Explain the transformations of carbon compounds in the carbon cycle.

Explain the transformations of carbon compounds in the carbon cycle.

Explain the transformations of carbon compounds in the carbon cycle.

State the distance from the city centre at which the highest proportion of plants sampled contained HCN.

State the distance from the city centre at which the highest proportion of plants sampled contained HCN.

State the distance from the city centre at which the highest proportion of plants sampled contained HCN.

Outline the relationship shown in the graph.

Outline the relationship shown in the graph.

Outline the relationship shown in the graph.

Deduce whether the pattern of cyanogenesis was the same in all of the areas around all four cities.

The graph shows atmospheric oxygen levels over time.

About 2.5 billion years ago, a significant rise in atmospheric oxygen occurred. What was the cause of this rise?

A. Photosynthesis by non-vascular land plants

B. Photosynthesis by vascular land plants

C. Oxygen produced by photosynthetic bacteria being released from the ocean into the atmosphere

D. Volcanic activity

The graph shows atmospheric oxygen levels over time.

About 2.5 billion years ago, a significant rise in atmospheric oxygen occurred. What was the cause of this rise?

A. Photosynthesis by non-vascular land plants

B. Photosynthesis by vascular land plants

C. Oxygen produced by photosynthetic bacteria being released from the ocean into the atmosphere

D. Volcanic activity

The map shows the widespread distribution of coral reef ecosystems (indicated by black dots) in the world’s oceans. Death of coral reefs is related to increasing atmospheric carbon dioxide concentrations.

[Source: National Oceanic and Atmospheric Administration, 2021. Where Reef Building Corals Found. [map online] Available at: https://oceanservice.noaa.gov/education/tutorial_corals/media/supp_coral05a.html [Accessed 20 May 2021].]

Explain how increased atmospheric carbon dioxide concentrations can lead to coral death.

The map shows the widespread distribution of coral reef ecosystems (indicated by black dots) in the world’s oceans. Death of coral reefs is related to increasing atmospheric carbon dioxide concentrations.

[Source: National Oceanic and Atmospheric Administration, 2021. Where Reef Building Corals Found. [map online] Available at: https://oceanservice.noaa.gov/education/tutorial_corals/media/supp_coral05a.html [Accessed 20 May 2021].]

Explain how increased atmospheric carbon dioxide concentrations can lead to coral death.

The map shows the widespread distribution of coral reef ecosystems (indicated by black dots) in the world’s oceans. Death of coral reefs is related to increasing atmospheric carbon dioxide concentrations.

[Source: National Oceanic and Atmospheric Administration, 2021. Where Reef Building Corals Found. [map online] Available at: https://oceanservice.noaa.gov/education/tutorial_corals/media/supp_coral05a.html [Accessed 20 May 2021].]

Explain how increased atmospheric carbon dioxide concentrations can lead to coral death.

Deduce whether the pattern of cyanogenesis was the same in all of the areas around all four cities.

Deduce whether the pattern of cyanogenesis was the same in all of the areas around all four cities.

Discuss whether the data supports the hypothesis that the gradient in cyanogenesis is due to its benefits against herbivory in rural areas.

Discuss whether the data supports the hypothesis that the gradient in cyanogenesis is due to its benefits against herbivory in rural areas.

Discuss whether the data supports the hypothesis that the gradient in cyanogenesis is due to its benefits against herbivory in rural areas.

Using all of the data so far, suggest whether exposure to freezing temperatures in the four cities is supported as a reason for the differences in HCN production in T. repens.

Using all of the data so far, suggest whether exposure to freezing temperatures in the four cities is supported as a reason for the differences in HCN production in T. repens.

Using all of the data so far, suggest whether exposure to freezing temperatures in the four cities is supported as a reason for the differences in HCN production in T. repens.

Distinguish between the transfers of energy and inorganic nutrients in ecosystems.

Distinguish between the transfers of energy and inorganic nutrients in ecosystems.

Distinguish between the transfers of energy and inorganic nutrients in ecosystems.

Discuss the relationship between atmospheric carbon dioxide concentration and global temperatures.

Using the data, outline the different use of thiamethoxam in North and South America.

Outline the role of methanogenic archaeans in the movement of carbon in ecosystems.

Outline the role of methanogenic archaeans in the movement of carbon in ecosystems.

Outline the role of methanogenic archaeans in the movement of carbon in ecosystems.

Describe how autotrophs absorb light energy

Describe how autotrophs absorb light energy

Describe how autotrophs absorb light energy

Using the data, outline the different use of thiamethoxam in North and South America.

Using the data, outline the different use of thiamethoxam in North and South America.

Discuss the relationship between atmospheric carbon dioxide concentration and global temperatures.

Identify the total percentage of honey samples contaminated with neonicotinoid pesticides in the continent with the lowest overall levels of contamination.

. . . . . . . . . . . . %

Discuss the relationship between atmospheric carbon dioxide concentration and global temperatures.

Identify the total percentage of honey samples contaminated with neonicotinoid pesticides in the continent with the lowest overall levels of contamination.

. . . . . . . . . . . . %

Identify the total percentage of honey samples contaminated with neonicotinoid pesticides in the continent with the lowest overall levels of contamination.

. . . . . . . . . . . . %

Deduce the conclusions that can be drawn from the data in the graph.

Deduce the conclusions that can be drawn from the data in the graph.

Deduce the conclusions that can be drawn from the data in the graph.

Suggest a reason for the effect of a diet reduced in acetylcholine on the larval survival rate.

Suggest a reason for the effect of a diet reduced in acetylcholine on the larval survival rate.

Suggest a reason for the effect of a diet reduced in acetylcholine on the larval survival rate.

Compare and contrast the effect of clothianidin and thiacloprid treatments on the concentration of acetylcholine in royal jelly.

Compare and contrast the effect of clothianidin and thiacloprid treatments on the concentration of acetylcholine in royal jelly.

Compare and contrast the effect of clothianidin and thiacloprid treatments on the concentration of acetylcholine in royal jelly.

State one process that results in the loss of carbon dioxide from a marine organism such as a crustacean or a jellyfish.

State one process that results in the loss of carbon dioxide from a marine organism such as a crustacean or a jellyfish.

State one process that results in the loss of carbon dioxide from a marine organism such as a crustacean or a jellyfish.

The crustacean and the jellyfish obtain carbon compounds by feeding. State one source of carbon for marine organisms, other than feeding.

The crustacean and the jellyfish obtain carbon compounds by feeding. State one source of carbon for marine organisms, other than feeding.

The crustacean and the jellyfish obtain carbon compounds by feeding. State one source of carbon for marine organisms, other than feeding.

Explain how energy enters, flows through and is lost from marine food chains.

Outline the criteria that should be used to assess whether a group of organisms is a species.

Outline the criteria that should be used to assess whether a group of organisms is a species.

Outline the criteria that should be used to assess whether a group of organisms is a species.

Explain how energy enters, flows through and is lost from marine food chains.

Explain how energy enters, flows through and is lost from marine food chains.

Deduce whether jellyfish or crustacea are a richer source of carbon in a food chain.

Deduce whether jellyfish or crustacea are a richer source of carbon in a food chain.

Deduce whether jellyfish or crustacea are a richer source of carbon in a food chain.

Suggest with a reason whether having a large body mass is an advantage or disadvantage for jellyfish.

Suggest with a reason whether having a large body mass is an advantage or disadvantage for jellyfish.

Suggest with a reason whether having a large body mass is an advantage or disadvantage for jellyfish.

Describe the evidence that is provided by the data in the table for the harmful effects of rising sea temperatures on corals.

Describe the evidence that is provided by the data in the table for the harmful effects of rising sea temperatures on corals.

Describe the evidence that is provided by the data in the table for the harmful effects of rising sea temperatures on corals.

The diagram shows the flow of energy through an ecosystem in ${\text{kJ\hspace{0.05em}m}}^{–2}{\text{\hspace{0.05em}y}}^{–1}.$

The diagram shows the carbon flux in gigatonnes per year between some of the Earth’s global reservoirs.

[Source: Figure 7.3 and Table 7.1 from Denman, K.L., G. Brasseur, A. Chidthaisong, P. Ciais, P.M. Cox, R.E. Dickinson, D.
Hauglustaine, C. Heinze, E. Holland, D. Jacob, U. Lohmann, S Ramachandran, P.L. da Silva Dias, S.C. Wofsy and
X. Zhang, 2007: Couplings Between Changes in the Climate System and Biogeochemistry. In: Climate Change
2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt,
M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.]

What can be deduced from the information in the diagram?

A. Arrows S are mainly due to respiration of marine plants and animals.

B. Photosynthesis is a component of both arrows Q and S.

C. Every day, more carbon is removed from the ocean than is added.

D. Ocean carbon is stored as dissolved calcium carbonate.

The researchers concluded that there was a threshold coral cover percentage, below which infection rates tended to remain fairly low. Using the data in the table, identify this threshold level.

The diagram shows the flow of energy through an ecosystem in ${\text{kJ\hspace{0.05em}m}}^{–2}{\text{\hspace{0.05em}y}}^{–1}.$

The diagram shows the carbon flux in gigatonnes per year between some of the Earth’s global reservoirs.

[Source: Figure 7.3 and Table 7.1 from Denman, K.L., G. Brasseur, A. Chidthaisong, P. Ciais, P.M. Cox, R.E. Dickinson, D.
Hauglustaine, C. Heinze, E. Holland, D. Jacob, U. Lohmann, S Ramachandran, P.L. da Silva Dias, S.C. Wofsy and
X. Zhang, 2007: Couplings Between Changes in the Climate System and Biogeochemistry. In: Climate Change
2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt,
M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.]

What can be deduced from the information in the diagram?

A. Arrows S are mainly due to respiration of marine plants and animals.

B. Photosynthesis is a component of both arrows Q and S.

C. Every day, more carbon is removed from the ocean than is added.

D. Ocean carbon is stored as dissolved calcium carbonate.

Which gases have made the most significant contributions to global warming?

A. Water and carbon dioxide

B. Carbon dioxide and methane

C. Methane and nitrous oxide

D. Carbon dioxide and ozone

The researchers concluded that there was a threshold coral cover percentage, below which infection rates tended to remain fairly low. Using the data in the table, identify this threshold level.

The researchers concluded that there was a threshold coral cover percentage, below which infection rates tended to remain fairly low. Using the data in the table, identify this threshold level.

Calculate the increase in mean global temperature between 1880 and 2010.

.......... °C

Suggest a reason for a larger percentage of corals being infected with white syndrome on reefs with a higher cover of corals.

Suggest a reason for a larger percentage of corals being infected with white syndrome on reefs with a higher cover of corals.

Suggest a reason for a larger percentage of corals being infected with white syndrome on reefs with a higher cover of corals.

Compare and contrast the data for 1998–1999 and 2002–2003.

Compare and contrast the data for 1998–1999 and 2002–2003.

Compare and contrast the data for 1998–1999 and 2002–2003.

Some scientists predict that, if humans continue to produce carbon dioxide at the current rate, the pH of the oceans will become more acidic. Suggest possible effects on the coral reefs.

Which gases have made the most significant contributions to global warming?

A. Water and carbon dioxide

B. Carbon dioxide and methane

C. Methane and nitrous oxide

D. Carbon dioxide and ozone

Calculate the increase in mean global temperature between 1880 and 2010.

.......... °C

Some scientists predict that, if humans continue to produce carbon dioxide at the current rate, the pH of the oceans will become more acidic. Suggest possible effects on the coral reefs.

Some scientists predict that, if humans continue to produce carbon dioxide at the current rate, the pH of the oceans will become more acidic. Suggest possible effects on the coral reefs.

Calculate the increase in mean global temperature between 1880 and 2010.

.......... °C

Explain how increased carbon dioxide in the air leads to the greenhouse effect.

Explain how increased carbon dioxide in the air leads to the greenhouse effect.

Explain how increased carbon dioxide in the air leads to the greenhouse effect.

Outline energy flow through a community in a natural ecosystem.

The image shows an example of a soil food web.

[Source: Anon., n.d. The Soil Food Web. [image online] Available at: https://www.nrcs.usda.gov/wps/portal/nrcs/
photogallery/soils/health/biology/gallery/?cid=1788&position=Promo [Accessed 11 March 2020].]

Draw a food chain from this food web, showing at least three organisms.

Outline energy flow through a community in a natural ecosystem.

The image shows an example of a soil food web.

[Source: Anon., n.d. The Soil Food Web. [image online] Available at: https://www.nrcs.usda.gov/wps/portal/nrcs/
photogallery/soils/health/biology/gallery/?cid=1788&position=Promo [Accessed 11 March 2020].]

Draw a food chain from this food web, showing at least three organisms.

The image shows an example of a soil food web.

[Source: Anon., n.d. The Soil Food Web. [image online] Available at: https://www.nrcs.usda.gov/wps/portal/nrcs/
photogallery/soils/health/biology/gallery/?cid=1788&position=Promo [Accessed 11 March 2020].]

Draw a food chain from this food web, showing at least three organisms.

Outline energy flow through a community in a natural ecosystem.

Explain the reasons for food chains rarely containing more than four or five trophic levels.

Explain the reasons for food chains rarely containing more than four or five trophic levels.

Explain the reasons for food chains rarely containing more than four or five trophic levels.

Describe the effect of temperature on the total biomass.

Describe the effect of temperature on the total biomass.

Describe the effect of temperature on the total biomass.

Compare and contrast the effects of temperature on the biomass of autotrophs and heterotrophs with added nutrients.

Compare and contrast the effects of temperature on the biomass of autotrophs and heterotrophs with added nutrients.

Compare and contrast the effects of temperature on the biomass of autotrophs and heterotrophs with added nutrients.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Suggest reasons for the decreases in biomass of autotrophs as temperature rises, despite the increases in photosynthesis.

Suggest reasons for the decreases in biomass of autotrophs as temperature rises, despite the increases in photosynthesis.

Suggest reasons for the decreases in biomass of autotrophs as temperature rises, despite the increases in photosynthesis.

Explain how increased levels of atmospheric carbon dioxide contribute to global warming.

Suggest two abiotic factors, other than temperature and nutrient supply, that may affect the production of biomass of the grasslands.

Suggest two abiotic factors, other than temperature and nutrient supply, that may affect the production of biomass of the grasslands.

Suggest two abiotic factors, other than temperature and nutrient supply, that may affect the production of biomass of the grasslands.

Explain how increased levels of atmospheric carbon dioxide contribute to global warming.

Explain how increased levels of atmospheric carbon dioxide contribute to global warming.

State the mean annual decline in insect biomass.

State the mean annual decline in insect biomass.

State the mean annual decline in insect biomass.

The diagram shows part of the carbon cycle involving methane.

[Source: NASA GISS, n.d. Rough schematic of methane sources and sinks. [diagram online] Available at:
https://www.giss.nasa.gov/research/features/200409_methane/ [Accessed 26 October 2021].]

Which conditions favour methane production in W, X and Y?

A.  Presence of eubacteria and organic matter

B.  Presence of archaeans and waterlogged soil

C.  Presence of eubacteria and waterlogged soil

D.  Presence of archaeans and oxygen

The diagram shows part of the carbon cycle involving methane.

[Source: NASA GISS, n.d. Rough schematic of methane sources and sinks. [diagram online] Available at:
https://www.giss.nasa.gov/research/features/200409_methane/ [Accessed 26 October 2021].]

Which conditions favour methane production in W, X and Y?

A.  Presence of eubacteria and organic matter

B.  Presence of archaeans and waterlogged soil

C.  Presence of eubacteria and waterlogged soil

D.  Presence of archaeans and oxygen

Calculate the number of Coleoptera species that would be expected to exist after one year from a starting number of 400$$000 species, assuming the mean rate of decline.

Carbon sinks are any reservoirs that absorb and store carbon dioxide from the atmosphere. Which process increases the size of the carbon sink in oceans?

A.  Photosynthesis

B.  Respiration

C.  Ocean acidification

D.  Decomposition

Calculate the number of Coleoptera species that would be expected to exist after one year from a starting number of 400$$000 species, assuming the mean rate of decline.

Calculate the number of Coleoptera species that would be expected to exist after one year from a starting number of 400$$000 species, assuming the mean rate of decline.

Carbon sinks are any reservoirs that absorb and store carbon dioxide from the atmosphere. Which process increases the size of the carbon sink in oceans?

A.  Photosynthesis

B.  Respiration

C.  Ocean acidification

D.  Decomposition

By the end of the 19th century in England, the dark form of the moth Biston betularia formed up to 98$$% of the total population in industrial areas. From 1970, the percentage of dark forms decreased significantly. What is an explanation for the decrease?

A.  An increase in environmental pollution killed the dark forms more than the light forms.

B.  Reduction of pollution resulted in greater camouflage for light forms of the moth.

C.  Dark forms could no longer find mates.

D.  Light forms had superior feeding mechanisms.

By the end of the 19th century in England, the dark form of the moth Biston betularia formed up to 98$$% of the total population in industrial areas. From 1970, the percentage of dark forms decreased significantly. What is an explanation for the decrease?

A.  An increase in environmental pollution killed the dark forms more than the light forms.

B.  Reduction of pollution resulted in greater camouflage for light forms of the moth.

C.  Dark forms could no longer find mates.

D.  Light forms had superior feeding mechanisms.

The table shows the presence or absence of four finches from the Geospizinae subfamily on seven of the Galapagos Islands. Cactus finches feed on cacti and warbler finches feed on insects or seeds. Presence on an island is indicated by a tick.

What might be a reason for the distribution of the large cactus finch?

A.  Cacti are only found on Española.

B.  Large cactus finches on other islands all flew to Española.

C.  The beaks of large cactus finches on Floreana changed in order to feed on other sources.

D.  A variation of the beak in a finch on Española enabled it to feed successfully on a cactus.

Compare and contrast the results for the 1:1 and the 1:10 P:L diets.

The table shows the presence or absence of four finches from the Geospizinae subfamily on seven of the Galapagos Islands. Cactus finches feed on cacti and warbler finches feed on insects or seeds. Presence on an island is indicated by a tick.

What might be a reason for the distribution of the large cactus finch?

A.  Cacti are only found on Española.

B.  Large cactus finches on other islands all flew to Española.

C.  The beaks of large cactus finches on Floreana changed in order to feed on other sources.

D.  A variation of the beak in a finch on Española enabled it to feed successfully on a cactus.

Compare and contrast the results for the 1:1 and the 1:10 P:L diets.

Compare and contrast the results for the 1:1 and the 1:10 P:L diets.

Suggest a reason that the mass of protein and lipid mixture eaten at 25:1 is lower than at 50:1.

Suggest a reason that the mass of protein and lipid mixture eaten at 25:1 is lower than at 50:1.

Suggest a reason that the mass of protein and lipid mixture eaten at 25:1 is lower than at 50:1.

Suggest with a reason which P:L diet is closest to the normal diet of these bumblebees.

Suggest with a reason which P:L diet is closest to the normal diet of these bumblebees.

Suggest with a reason which P:L diet is closest to the normal diet of these bumblebees.

Outline how energy flows in an ecosystem.

Outline how energy flows in an ecosystem.

Outline how energy flows in an ecosystem.

Outline how the shrew labelled P differs from the normal relationship between BCH and brain mass.

Outline how the shrew labelled P differs from the normal relationship between BCH and brain mass.

Outline how the shrew labelled P differs from the normal relationship between BCH and brain mass.

State the season when shrew brain mass is greatest.

State the season when shrew brain mass is greatest.

State the season when shrew brain mass is greatest.

Compare and contrast the results for winter and spring.

Compare and contrast the results for winter and spring.

Compare and contrast the results for winter and spring.

Suggest a reason for the difference in BCH in summer and winter.

Suggest a reason for the difference in BCH in summer and winter.

Suggest a reason for the difference in BCH in summer and winter.

State the activity and season that occupied the greatest mean percentage of observation time.

State the activity and season that occupied the greatest mean percentage of observation time.

State the activity and season that occupied the greatest mean percentage of observation time.

Calculate the percentage of containers that contained food.

Calculate the percentage of containers that contained food.

Calculate the percentage of containers that contained food.

Outline a reason that the path length was standardized.

Outline a reason that the path length was standardized.

Outline a reason that the path length was standardized.

Compare and contrast the results for trials 2 and 9.

Compare and contrast the results for trials 2 and 9.

Compare and contrast the results for trials 2 and 9.

It has been argued that variation in the global mean surface temperature has been caused by variation in energy from the Sun. Analyse whether evidence from the graphs supports this argument.

It has been argued that variation in the global mean surface temperature has been caused by variation in energy from the Sun. Analyse whether evidence from the graphs supports this argument.

It has been argued that variation in the global mean surface temperature has been caused by variation in energy from the Sun. Analyse whether evidence from the graphs supports this argument.

Explain how temperature affects enzymes.

Explain how temperature affects enzymes.

Explain how temperature affects enzymes.

Describe how plants are named and classified, including recognition features of plant phyla.

Describe how plants are named and classified, including recognition features of plant phyla.

Describe how plants are named and classified, including recognition features of plant phyla.

Humans have persecuted predators such as coyotes (Canis latrans), causing severe reduction in the number of large carnivores throughout the world. The diagram represents part of a food web in Texas, USA.

_{[Source: Coyote: https://commons.wikimedia.org/wiki/File:2009-Coyote-Yosemite.jpg. CC-BY-SA 3.0; Yathin S. Krishnappa, Jan.
2009, Coyote from Yosemite National Park, California in snow.]
[Source: Fox: https://commons.wikimedia.org/wiki/File:Foxes_of_Island_Beach_State_Park_New_Jersey_(16324545492).jpg.
CC-Attribution 2.0; Anthony Quintano, Jan. 2015, Foxes of Island Beach State Park New Jersey.]
[Source: Rodent/Brown Rat: https://commons.wikimedia.org/wiki/File:Rattus_norvegicus_-_Brown_rat_02.jpg. CC-BY-SA-4.0
Zeynel Cebeci, May 2020; Brown Rat, Adana, Turkey.]
[Source: Lagomorph: https://commons.wikimedia.org/wiki/File:Eastern_Cottontail.JPG. CC 3.0. Taken by Gareth Rasberry,
Huntington Beach State Park, Murrells Inlet, South Carolina, USA.]
[Source: Nest Eggs: https://commons.wikimedia.org/wiki/File:Eastern_Phoebe-nest-Brown-headed-Cowbird-egg.jpg. CC 3.0.
Galawebdesign, June 2007, Eastern Phoebe (Sayornis phoebe) nest with one Brown-headed Cowbird (Molothrus ater)
egg.]}

What is a possible outcome for the lagomorph population in this ecosystem if coyote numbers were controlled by killing them to reduce losses of domestic livestock?

A.  Decrease because there are fewer predators

B.  Increase because there are fewer foxes to eat them

C.  Decrease because there are more rodents for foxes to eat

D.  Increase because, although there are more foxes, there are also more rodents

Humans have persecuted predators such as coyotes (Canis latrans), causing severe reduction in the number of large carnivores throughout the world. The diagram represents part of a food web in Texas, USA.

_{[Source: Coyote: https://commons.wikimedia.org/wiki/File:2009-Coyote-Yosemite.jpg. CC-BY-SA 3.0; Yathin S. Krishnappa, Jan.
2009, Coyote from Yosemite National Park, California in snow.]
[Source: Fox: https://commons.wikimedia.org/wiki/File:Foxes_of_Island_Beach_State_Park_New_Jersey_(16324545492).jpg.
CC-Attribution 2.0; Anthony Quintano, Jan. 2015, Foxes of Island Beach State Park New Jersey.]
[Source: Rodent/Brown Rat: https://commons.wikimedia.org/wiki/File:Rattus_norvegicus_-_Brown_rat_02.jpg. CC-BY-SA-4.0
Zeynel Cebeci, May 2020; Brown Rat, Adana, Turkey.]
[Source: Lagomorph: https://commons.wikimedia.org/wiki/File:Eastern_Cottontail.JPG. CC 3.0. Taken by Gareth Rasberry,
Huntington Beach State Park, Murrells Inlet, South Carolina, USA.]
[Source: Nest Eggs: https://commons.wikimedia.org/wiki/File:Eastern_Phoebe-nest-Brown-headed-Cowbird-egg.jpg. CC 3.0.
Galawebdesign, June 2007, Eastern Phoebe (Sayornis phoebe) nest with one Brown-headed Cowbird (Molothrus ater)
egg.]}

What is a possible outcome for the lagomorph population in this ecosystem if coyote numbers were controlled by killing them to reduce losses of domestic livestock?

A.  Decrease because there are fewer predators

B.  Increase because there are fewer foxes to eat them

C.  Decrease because there are more rodents for foxes to eat

D.  Increase because, although there are more foxes, there are also more rodents

Explain how changes to the cell cycle can result in tumour formation.

Explain how changes to the cell cycle can result in tumour formation.

Explain how changes to the cell cycle can result in tumour formation.

Label with a P on the $x$-axis the level of commercial sea fishing activity that would result in maximum sustainability.

Label with a P on the $x$-axis the level of commercial sea fishing activity that would result in maximum sustainability.

Label with a P on the $x$-axis the level of commercial sea fishing activity that would result in maximum sustainability.

State two variables measured by the probes.

1: 

2: 

State two variables measured by the probes.

1: 

2: 

State two variables measured by the probes.

1: 

2: 

Duckweed (Lemna gibba) is a plant that grows on the surface of water. It was grown in cultures and the percentage increase in total area covered per day was obtained. The graph shows the specific growth rates per day for duckweed measured over 22 days.

^{[Source: Material from: Mkandawire, M. and Dudel, E.G., Assignment of Lemna gibba L. (duckweed) bioassay for in situ
ecotoxicity assessment, published 2005, Aquatic Ecology, reproduced with permission of SNCSC.]}

Suggest reasons for the slowing down of duckweed population growth after day 6.

Duckweed (Lemna gibba) is a plant that grows on the surface of water. It was grown in cultures and the percentage increase in total area covered per day was obtained. The graph shows the specific growth rates per day for duckweed measured over 22 days.

^{[Source: Material from: Mkandawire, M. and Dudel, E.G., Assignment of Lemna gibba L. (duckweed) bioassay for in situ
ecotoxicity assessment, published 2005, Aquatic Ecology, reproduced with permission of SNCSC.]}

Suggest reasons for the slowing down of duckweed population growth after day 6.

The pie chart shows the modes of nutrition of fungi in Huahu Lake wetland in China.

_{[Source: Fei Xie, Anzhou Ma, Hanchang Zhou, Yu Liang, Jun Yin, Ke Ma, Xuliang Zhuang and Guoqiang Zhuang, 2020.
Revealing Fungal Communities in Alpine Wetlands through Species Diversity, Functional Diversity and Ecological
Network Diversity. Microorganisms, 8, p. 632. Open Access.]} 

What is the most common mode of nutrition of fungi in this wetland?

A.  Heterotrophic fungi that feed on living organisms by ingestion

B.  Autotrophic fungi that obtain organic nutrients from detritus by internal digestion

C.  Fungi that have either an autotrophic or heterotrophic method of nutrition

D.  Heterotrophic fungi obtaining nutrients from dead organisms by external digestion

The pie chart shows the modes of nutrition of fungi in Huahu Lake wetland in China.

_{[Source: Fei Xie, Anzhou Ma, Hanchang Zhou, Yu Liang, Jun Yin, Ke Ma, Xuliang Zhuang and Guoqiang Zhuang, 2020.
Revealing Fungal Communities in Alpine Wetlands through Species Diversity, Functional Diversity and Ecological
Network Diversity. Microorganisms, 8, p. 632. Open Access.]} 

What is the most common mode of nutrition of fungi in this wetland?

A.  Heterotrophic fungi that feed on living organisms by ingestion

B.  Autotrophic fungi that obtain organic nutrients from detritus by internal digestion

C.  Fungi that have either an autotrophic or heterotrophic method of nutrition

D.  Heterotrophic fungi obtaining nutrients from dead organisms by external digestion

The pie chart shows the modes of nutrition of fungi in Huahu Lake wetland in China.

_{[Source: Fei Xie, Anzhou Ma, Hanchang Zhou, Yu Liang, Jun Yin, Ke Ma, Xuliang Zhuang and Guoqiang Zhuang, 2020.
Revealing Fungal Communities in Alpine Wetlands through Species Diversity, Functional Diversity and Ecological
Network Diversity. Microorganisms, 8, p. 632. Open Access.]} 

What is the most common mode of nutrition of fungi in this wetland?

A.  Heterotrophic fungi that feed on living organisms by ingestion

B.  Autotrophic fungi that obtain organic nutrients from detritus by internal digestion

C.  Fungi that have either an autotrophic or heterotrophic method of nutrition

D.  Heterotrophic fungi obtaining nutrients from dead organisms by external digestion

The pie chart shows the modes of nutrition of fungi in Huahu Lake wetland in China.

_{[Source: Fei Xie, Anzhou Ma, Hanchang Zhou, Yu Liang, Jun Yin, Ke Ma, Xuliang Zhuang and Guoqiang Zhuang, 2020.
Revealing Fungal Communities in Alpine Wetlands through Species Diversity, Functional Diversity and Ecological
Network Diversity. Microorganisms, 8, p. 632. Open Access.]} 

What is the most common mode of nutrition of fungi in this wetland?

A.  Heterotrophic fungi that feed on living organisms by ingestion

B.  Autotrophic fungi that obtain organic nutrients from detritus by internal digestion

C.  Fungi that have either an autotrophic or heterotrophic method of nutrition

D.  Heterotrophic fungi obtaining nutrients from dead organisms by external digestion