Ecology Study

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The graph below shows the monthly mean values of terrestrial invertebrates from May 1997 to June 1998 in the northern hemisphere. The light line shows the biomass of invertebrates which are prey to forest birds (terrestrial invertebrate biomass). The darker line shows the invertebrates which lived in the stream and have moved to the forest (aquatic invertebrate flux or movement). The black bars on the horizontal line at the bottom show periods when trees have leaves and the white bars show periods of defoliation. Suggest a possible explanation for the pattern in aquatic invertebrate flux to the forest seen between the months of June and December.

(aquatic invertebrate flux) decreases because movement to the forest has occurred (by adult forms) / fewer aquatic invertebrates left in the stream so fewer are moving; fluctuation due to movement of different species/different life cycles/second generation; decreases because invertebrates left at the beginning of winter/cold season; (adult forms) move to utilize (changes in) food supply in forest;

Reproduction in fish is called spawning. The males and females in a population that are mature enough to reproduce are the spawning stock. In order to provide better fisheries management and conservation decisions, there is a need to investigate the relationship between spawning stock and environmental conditions. The graph shows the North Sea cod spawning biomass and sea surface temperatures. Outline the trends in North Sea cod spawning biomass between 1960 and 2000.

(rapid) increase between 1960 and 1970; decrease from 1970 to beyond 2000/2002: brief reversal/slight increase between 1981 and 1982;

Which hypothesis is supported by evidence from ecological research? A. Decomposers are the final stage in the food chain. B. Producers depend upon consumers more than on decomposers. C. Decomposers help to recycle energy from food chains. D. Producers use nutrients that decomposers help to recycle.

D. Producers use nutrients that decomposers help to recycle.

What is the mode of nutrition of midge larva? A. Autotroph B. Detritivore C. Heterotroph D. Saprotroph

D. Saprotroph

150 (allow answers in the range 140-160)

Which represents a correct food chain from this web? A. stickleback → midge larva → unicellular algae B. ciliates → Daphnia → stickleback → dragonfly nymph C. diatom → midge larva → caddisfly larva → stickleback D. filamentous algae → mayfly nymph → leech → stickleback

C. diatom → midge larva → caddisfly larva → stickleback

The energy passing from the detritivores to the predatory invertebrates in this food web is 14 000 kJ m-2 year-1. Approximately how much energy (in kJ m-2 year-1) passes from the predatory invertebrates to the carnivores? A. 140 B. 1400 C. 14 000 D. 140 000

1400

150 (allow answers in the range 140-160)

The graph below shows the monthly mean values of terrestrial invertebrates from May 1997 to June 1998 in the northern hemisphere. The light line shows the biomass of invertebrates which are prey to forest birds (terrestrial invertebrate biomass). The darker line shows the invertebrates which lived in the stream and have moved to the forest (aquatic invertebrate flux or movement). The black bars on the horizontal line at the bottom show periods when trees have leaves and the white bars show periods of defoliation. State the mean terrestrial invertebrate biomass measured in August.

166 mg m−2 (Allow answers in the range of 162-168 mg m−2 )

The grey partridge (Perdix perdix) is a species of bird that is found on farmland. Sparrowhawks (Accipiter nisus) and buzzards (Buteo buteo) are birds of prey that kill and feed on birds, including grey partridge. The number of grey partridges in a region of southern England was monitored from 1970 to 2004. The numbers of sparrowhawks and buzzards, seen from sampling positions during regular observation periods, were counted. The results are shown in the graph below. The density of grey partridge (number per square kilometre) varied considerably in different areas within the study region. The graph below shows the correlation between the density of grey partridges and the density of birds of prey. The highest density of birds of prey was found in areas used for recreational shooting. In these areas, other species of partridge were bred and released. Food and shelter were provided for the released birds. These measures tended to increase the number of both released and wild birds. The causes of death of grey partridge were investigated in one of the areas that was used for recreational shooting. The pie chart below shows the causes of death. Calculate the percentage of deaths due to birds of prey.

18%/18.1% (18 needed but no penalty if significant figure error)

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. State the largest number of dolphins counted in a single survey.

2200 (allow answers in the range 2175-2225)

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Calculate the mean number of dolphins counted per survey for the winter season.

800 (allow answers in the range 750-850)

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Calculate the mean number of dolphins counted per survey for the winter season.

800 (allow answers in the range 750-850)

The table shows the monthly CO2 concentrations in mg L-1 taken at two monitoring stations. What is directly indicated by the data? A. CO2 concentration in the atmosphere varies from place to place. B. Cape Grim is less affected by global warming than Mauna Loa. C. CO2 creates a greenhouse effect at both locations. D. The standard deviation for Cape Grim is higher than standard deviation for Mauna Loa.

A. CO2 concentration in the atmosphere varies from place to place.

What is lost between trophic levels in ecosystems and cannot be recycled? A. Heat B. Nitrogen C. Carbon compounds D. Biomass

A. Heat

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

A. Increased rates of decomposition of detritus trapped in permafrost

The following graph refers to questions 19 and 20. It 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. Why does the amount of CO2 fall between April and August? A. Seasonal increase in the rate of photosynthesis in northern hemisphere forests B. Seasonal decrease in the rate of photosynthesis in northern hemisphere forests C. Seasonal decrease in the rate of fossil fuel consumption D. Seasonal increase in the amount of CO2 taken up by the oceans

A. Seasonal increase in the rate of photosynthesis in northern hemisphere forests

Describe what is meant by a food chain and a food web.

Accept examples of the points below, provided that the terms underlined are clearly identified. Accept only named examples (latin or common names) from natural ecosystems only. Do not award marks for general names such as "fish" or "tree". a. food chain shows transfer of nutrients/energy in an ecosystem / arrows from one trophic level to the next in examples; b. between different trophic levels / shown in a correct chain or web; c. starting with a producer; d. followed by at least two levels of consumers / shown in a correct chain or web; e. food web is the (branched) interaction of multiple food chains / cross arrows in examples; f. using (multiple) producers as a source; g. transferring nutrients/energy to consumers from different food chains; h. same consumer could be at different trophic levels in a food web;

In a pond, two species of fish feed on insects and worms. The insects feed on the green plants that live in the water. What constitutes a population in this ecosystem?

All the fish of one species

State an external feature that is different in: Mollusca and Annelida.

Annelida are segmented while Mollusca are not (visibly segmented); Annelida may have bristles/chetae/chaetae while Mollusca do not; Mollusca (may) have a (hard) shell while Annelida do not; Mollusca have a muscular/large foot while Annelida do not; other valid external difference;

Global warming has changed both the thickness and surface area of sea ice of the Arctic Ocean as well as the Southern Ocean that surrounds Antarctica. Sea ice is highly sensitive to changes in temperature. Scientists have calculated a long-term mean for the surface area of sea ice in the Arctic and in the Southern Ocean around Antarctica. This mean value is used as a reference to examine changes in ice extent. The graph shows the variations from this mean (zero line) over a period of time. Adélie penguins (Pygoscelis adeliae) are only found in Antarctica and need sea ice for feeding and nesting. Biologists are able to deduce how these penguins have responded to changes in their environment for the last 35 000 years, as the Antarctic conditions have preserved their bones and their nests. The image is a map of Antarctica and the surrounding Southern Ocean. It shows the trends in the length of the sea ice season (days of the year when sea ice is increasing) and the sites of nine Adélie penguin colonies. Describe the trends in the length of the sea ice season around the Antarctic Peninsula and in the Ross Sea.

Antarctic Peninsula: a. decrease/stable at the base of the peninsula / decrease in the area of the penguin colonies/West of the tip / increase/+1 above and below the peninsula / variable pattern; Ross Sea: b. sea ice is increasing / +1 in the Ross Sea / area below / North of the Ross Sea / lower Ross Sea / Southern part of Ross Sea/closest to the South pole is stable/no change to the length of the sea ice season / variable pattern;

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

B. I and II only

Which gas will enhance the greenhouse effect if released into the atmosphere? A. Hydrogen B. Oxide of nitrogen C. Oxygen D. Nitrogen

B. Oxide of nitrogen

The diagram represents the carbon cycle. Which process has the greatest relative role in transferring carbon? A. Decomposition B. Combustion C. Photosynthesis D. Cell respiration

C. Photosynthesis

Describe the relationship between the rise in the concentration of atmospheric carbon dioxide and the enhanced greenhouse effect. [5]

CO2 is a greenhouse gas; increases in CO2 increase/enhance the greenhouse effect; greenhouse effect is a natural phenomenon but not its increase; Earth receives short wave radiation from the sun;reradiated from Earth as longer wave radiation/infra red/heat; CO2 /greenhouse gases trap/absorb longer wave radiation/infra red/heat; global warming happened during same time/period as CO2 rise; CO2 concentration correlated (positively) with global temperature / global temperature increases as CO2 concentration increases; (causal) link accepted by most scientists; no proof that man-made increases in CO2 have caused global warming;

State an external feature that is different in: Cnidaria and Mollusca.

Cnidaria have radial symmetry while Mollusca have bilateral symmetry; Cnidaria have tentacles/nematocysts/stinging cells while Mollusca do not; Mollusca (may) have a (hard) shell while Cnidaria do not; Mollusca have a mouth and anus while Cnidaria have only one opening; Mollusca have a muscular/large foot while Cnidaria do not; other valid external difference;

In a pond, two species of fish feed on insects and worms. The insects feed on the green plants that live in the water. What constitutes a population in this ecosystem? A. All the living organisms B. All the animals C. All the fish D. All the fish of one species

D. All the fish of one species

How is peat formed?

From partially decomposed organic matter under anaerobic and acidic conditions in waterlogged soils

Define the terms fundamental niche

Fundamental niche: the potential niche / the niche the organism could occupy under ideal conditions / the full mode of existence given the adaptations of the species / OWTTE;

What best describes the mode of nutrition of a heterotroph?

It obtains organic molecules from other organisms.

Increasing carbon dioxide concentration in the atmosphere leads to acidification of the ocean. This in turn reduces the amount of dissolved calcium carbonate. A study was undertaken to investigate the effect of increasing the concentration of atmospheric carbon dioxide on the calcification rate of marine organisms. Calcification is the uptake of calcium into the bodies and shells of marine organisms. The study was undertaken inside Biosphere-2, a large-scale closed mesocosm. The graph shows the results of the data collection. Distinguish between the exchange of matter and energy with the surroundings in a closed mesocosm.

Matter does not exchange/enter/leave but energy exchanges/enters/leaves

Coral reefs are among the most spectacular ecosystems on Earth. They support a rich diversity of life and provide economic benefits to the people who use them. In Papua New Guinea in the Pacific Ocean north of Australia the following data were collected. Coral cover is the percentage of the reef surface covered by live-hard coral. In order to test the effect of temperature, live samples of a species of coral, Pocillopora damicornis, were placed in an experimental chamber at a constant pH, water depth and low light. All the coral samples were started at 26°C and half of them were rapidly increased to 30°C. The pie charts show the percentage of live and dead tissues at the end of the experiment. Acidification of the world's oceans is an increasing threat to the health of oceanic life including coral reefs. Corals perform calcification to create their calcium carbonate exteriors. An experiment was conducted on Heron Island, Southern Great Barrier Reef, Australia. For the experiment the pH was altered by dissolving carbon dioxide in the water. Three different coral species were used, with each test group at two different temperature ranges and three different pH values. The white line in each photograph represents 5 cm. suggest another marine animal that has parts made of calcium carbonate and may therefore be damaged due to ocean acidification.

Mollusca/named marine mollusc with a shell/crustacean/named marine crustacean/Porifera/sponges/named calcareous marine sponge Reject terrestrial examples. Reject sea shells, shellfish. Specific named examples must be verified if it is uncertain whether they have calcified parts.

What is recycled in an ecosystem?

Nitrogen and carbon are recycled but not energy.

Which group of organisms in the carbon cycle converts carbon into a form that is available to primary consumers?

Producers

Define realized niche

Realized niche:the actual niche / the niche restricted by competition and environmental variables / the niche resulting from the limits placed on the species / OWTTE;

Using the diagram, explain the interaction of short and long wave radiation with greenhouse gases in the atmosphere.

Short wave radiation/UV «shown as» having its origin in the Sun gives off light as short radiation Short wave radiation/UV «shown as» passing through the greenhouse gases «some reflected» Some short wave radiation/UV is absorbed by the Earth and some is reflected The reflected radiation is long wave radiation «reflected as heat» Long wave radiation/IR «shown as» being unable to pass through/being absorbed/reflected by the greenhouse gases Award marks for diagrammatic explanations of these marking points. Accept UV and IR as long as they are drawn with the correct wavelength.

Why do food chains in an ecosystem rarely contain more than five organisms?

The conversion of food into growth by an organism is not very efficient.

Describe how plants carry out gas exchange in the leaves. [5]

gases/O2 and CO2 enter/exit the leaf through the stomata; by diffusion / down the concentration gradient; photosynthesis maintains concentration gradients/high O2 and low CO2 in the leaf; guard cells open the stomata during the day / close the stomata at night; gases/O2/CO2 move through air spaces in the spongy (mesophyll); CO2 dissolves in moisture in (mesophyll) cell walls;

Human activity leading to the emission of greenhouse gases may be a cause of global warming. According to the precautionary principle, what should be done about greenhouse gas emission?

Take measures to lower greenhouse gas emission without further evidence

The statement is about the role of some bacteria in ecosystems: "Bacteria play an important role in recycling nutrients in ecosystems. They live on organic wastes and dead organisms and digest their molecules. They then absorb some of these molecules for their own metabolism, and the rest is used by other organisms" What is the mode of nutrition of these bacteria?

They are saprotrophs.

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Predict with a reason, using the data, which district has most farmland.

Toledo because it has the highest incidence of malaria in map/graph (and farmland has highest correlation to incidence of malaria in the table).

Native oyster populations are decreasing where rivers meet the ocean along the northwest coast of North America. These oyster populations are being attacked by a gastropod. It is known that oysters and gastropods have hard parts composed of calcium carbonate and that ocean acidification is increasing. Studies were carried out using juvenile oysters and gastropods to investigate the effects of acidification on the decrease in the population of oysters. The first step was to raise oysters in two different mesocosms. One had seawater at a normal concentration of CO2 and the other had sea water with a high concentration of CO2. Gastropods were raised in two further mesocosms with normal and high CO2 concentrations respectively. A juvenile gastropod will attack a juvenile oyster by using its tongue-like structure (radula) to drill a hole through the oyster shell. Once the hole has been drilled, the gastropod sucks out the soft flesh. Researchers investigated the shell thickness at the site of the drill hole in relation to the size of the oyster. The results are seen in this graph.Equal numbers of oysters raised in seawater with a normal CO2 concentration and in seawater with a high CO2 concentration were then presented together to the gastropod predators in seawater with a normal CO2 concentration. The same numbers of oysters from the two groups were also presented together to the gastropods in seawater with a high CO2 concentration. The bar charts show how many of the oysters were drilled by the gastropods and the mean size of drilled oysters. Suggest reasons for the differences in the numbers of oysters drilled, as shown in the bar charts. [2]

a. (because) shells are thinner/smaller when the oyster is raised in high CO2/lower pH OR «because» lower pH/higher acidity prevents/reduces deposition of calcium carbonate b. gastropods target smaller/thinner-shelled oysters more c. gastropods can eat/drill thin-shelled/smaller oysters at a faster rate (and move onto another) d. eating smaller oysters «from high CO2 environments» means given population of gastropods require more oysters for same food intake

The trout, Oncorhynchus mykiss, that live in West Brush Creek and Cement Creek also feed on the mayflies. Fishermen come to Colorado to catch and eat trout. Draw a diagram of part of a food web for the creeks in Colorado, including mayflies, humans, trout and bats.

a. arrow pointing from trout to human b. arrows pointing from mayflies to trout and bats Award [1 max] if answer does NOT show all 4 organisms.

Outline the causes and consequences of the enhanced greenhouse effect. [5]

burning of (fossil) fuels/coal/oil/gas releases carbon dioxide; deforestation/loss of ecosystems reduces carbon dioxide uptake; methane emitted from cattle/livestock/melting permafrost/waste dumps; heating of the atmosphere/global warming/climate change; melting of ice caps/glaciers/permafrost / sea level rise / floods / droughts / changes in ocean currents / more powerful hurricanes / extreme weather events / other abiotic consequence; changes in species distributions/migration patterns / increased decomposition rates / increases in pest/pathogen species / loss of ice habitats / other biotic consequence;

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Compare the trends in incidence of malaria for Toledo and Corozal.

a. both are stable from 1989 to 1992; b. both see upward spike in 1992; c. Corozal reaches its peak (one year) earlier / vice versa; d. Toledo rises after 1998 but Corozal continues to decline / Corozal at the end decreases almost to 0, while Toledo still have incidence at the end of the decade; e. Toledo has a higher incidence (throughout the decade) / vice versa; f. Toledo changes more rapidly than Corozal / vice versa;

Draw a labelled diagram of a pyramid of energy.

a. drawn in steps rather than triangle b. drawn to scale (should be at least 1/5 of the box below it) OR annotated with appropriate numeric values c. producer d. primary consumer e. secondary consumer Award no marks if a drawing has not been made. "Appropriate numeric values" should indicate scale so accept percentage or numbers.

identify a food chain with four or more organisms from the forest food web

a. food chain shows feeding/trophic relationships; b. showing which organism/animal eats which organism; c. showing the flow of energy from producer/autotroph to top consumer/top carnivore / through trophic levels;

Global warming has changed both the thickness and surface area of sea ice of the Arctic Ocean as well as the Southern Ocean that surrounds Antarctica. Sea ice is highly sensitive to changes in temperature. Scientists have calculated a long-term mean for the surface area of sea ice in the Arctic and in the Southern Ocean around Antarctica. This mean value is used as a reference to examine changes in ice extent. The graph shows the variations from this mean (zero line) over a period of time. Adélie penguins (Pygoscelis adeliae) are only found in Antarctica and need sea ice for feeding and nesting. Biologists are able to deduce how these penguins have responded to changes in their environment for the last 35 000 years, as the Antarctic conditions have preserved their bones and their nests. The image is a map of Antarctica and the surrounding Southern Ocean. It shows the trends in the length of the sea ice season (days of the year when sea ice is increasing) and the sites of nine Adélie penguin colonies. Discuss the use of Adélie penguins in studying the effects of global warming.

a. global warming leads to climate / environmental change; eg temperature change / ice melting b. stable ice associated with stable population / no climate change; c. ice changes associated with population changes; d. changes in penguin population size can indicate climate change / global warming; e. example of how climate change can alter population; eg prey availability / habitat loss; f. not all species will be affected in the same way (so care needed in applying conclusions more widely) g. there is information on changes of population over the past 35 000 years;

The diagram shows the greenhouse effect. Outline reasons for the change occurring at Z. [2]

a. greenhouse gases present (at Z) b. greenhouse gases «CO2, methane, nitrous oxide, water vapour» absorb long-wavelengths/infraredORlong wavelengths/infrared waves blocked from leaving the atmosphere c. (long-wavelengths/infrared absorbed and) reradiated/re-emitted (heat Earth)

One of the distinguishing features of the Archaea is that they are capable of inhabiting extreme environments such as extreme temperatures or anoxic conditions. Outline other extreme environments inhabited by the Archaea.

a. high salinity (halophiles); b. example of high salinity (eg Dead Sea, Great Salt Lake Utah); c. extreme pH (acidophiles/alkalinophiles); d. high pressure (barophiles) / deep oceans;

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Discuss whether malaria could be reduced by replacing farmland with natural ecosystems and replacing broadleaf hill forest with mixed hill forest.

a. if farming provides habitat for mosquitoes, then reducing it could reduce malaria / OWTTE; b. natural habitats provide predators, but farmland does not; c. changing native vegetation is not practical since plants are adapted to their environment/organisms have specific adaptations to their environments; d. might work to change broadleaf forest into mixed hill forest as much of broadleaf forest has high incidence of malaria and no part of mixed hill forest has high incidence of malaria / OWTTE; e. loss of habitat/loss of biodiversity results in less stable environment; f. the value of maintaining natural habitat must be balanced with the value of reduced malaria; g. farmland feeds the population, so cannot be replaced / OWTTE

The greenhouse effect is a naturally occurring process. State one greenhouse gas.

carbon dioxide / methane / oxides of nitrogen / water vapour / ozone / CFCs

deduce the trophic level of each organism identified in your food chain from (b)(i).

correct trophic levels eg: raspberry bush⎯⎯→chickadee ⎯⎯→bull snake⎯⎯→mountain lionproducer primary secondary tertiary consumerconsumer consumer

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Analyse the data in the map to find whether there is an association between rivers and the incidence of malaria.

a. in Cayo and/or Toledo the high incidence seems to be associated with rivers; b. however, along one river in Toledo there is no high incidence; c. in Belize District there is low incidence along the river / high incidence away from the river; d. Orange Walk/Stan Creek there is no clear association; e. (consequently) association of rivers with high incidence of malaria is inconclusive OWTTE;

Global warming has changed both the thickness and surface area of sea ice of the Arctic Ocean as well as the Southern Ocean that surrounds Antarctica. Sea ice is highly sensitive to changes in temperature. Scientists have calculated a long-term mean for the surface area of sea ice in the Arctic and in the Southern Ocean around Antarctica. This mean value is used as a reference to examine changes in ice extent. The graph shows the variations from this mean (zero line) over a period of time. Adélie penguins (Pygoscelis adeliae) are only found in Antarctica and need sea ice for feeding and nesting. Biologists are able to deduce how these penguins have responded to changes in their environment for the last 35 000 years, as the Antarctic conditions have preserved their bones and their nests. The image is a map of Antarctica and the surrounding Southern Ocean. It shows the trends in the length of the sea ice season (days of the year when sea ice is increasing) and the sites of nine Adélie penguin colonies. Distinguish between changes in the surface area of sea ice in the Arctic and Antarctica. [2]

a. in the Arctic ocean the surface area of sea ice has declined whereas in Antarctica the surface area has increased; b. the rate of change is greater for the Arctic than for Antarctica; c. there are greater fluctuations in the surface area of sea ice in Antarctica than in the Arctic; For mp a, it is acceptable if there is no comparative term such as "whereas" or "but";

Explain the processes by which energy enters and flows through ecosystems. [8]

a. light energy is the initial energy source for (all) organisms b. producers/autotrophs change light/radiant energy into chemical energyORproducers/autotrophs convert/trap light/radiant energy by photosynthesis c. producing C6H12O6 /sugars/carbohydrates d. carbon/organic compounds used for energy/growth/repair/storage e. compounds/energy pass as food along food chains/trophic levels WTTE f. cellular respiration releases energy as ATP from food g. energy is lost as heat (during cellular respiration) h. loss of energy at each trophic levelORonly approximately 10% of energy is passed to the next trophic level / 90% is lost at each trophic level i. energy lost in bones/hair when they die/not fully eaten by the next trophic level j. energy lost in feces/urine k. decomposers/saprotrophs remove energy from wastes/bodies l. energy is not recycled

Discuss the definition of the term species.

a. meaning of species has changed over time / no longer just based on morphological features/phenotype; b. species members also resemble each other in physiology/biochemistry/DNA sequences/use of habitat/behaviour; c. but species can evolve and features change/species gradually split up; d. definition now based on ability to interbreed/produce viable, fertile offspring; e. gene flow among populations of the species maintains the species' uniqueness; f. some interspecific hybrids are fertile making categorization difficult; g. further accurate discussion point about species definition;

Most of the surface of the Earth is covered with a wide diversity of ecosystems. Outline two general characteristics of all ecosystems.

a. organisms/community plus the environment / biotic and abiotic «components» b. interactions c. ecosystems show sustainability d. nutrients are recycled in ecosystems e. energy flows through ecosystems f. producers «are part of all ecosystems» g. decomposers/saprotrophs «are part of all ecosystems»

The short-tailed albatross (Phoebastria albatrus) nests and breeds on remote low-lying coral islands in the Pacific Ocean. Predict how global warming may threaten the survival of such an ocean bird.

a. rising ocean levels/more extreme weather «due to global warming» may destroy breeding/nesting sites OR rising sea level may put island underwater causing young birds/chicks to drown b. populations may not find/adapt to new colony sites c. warming seas may affect the food supply

Mean annual chlorophyll concentration was measured in surface water of Narragansett Bay along the Atlantic coast of the USA, from 1971 to 2006. Field data of chlorophyll concentrations are shown below. Mesocosm experiments using water from Narragansett Bay were completed in the laboratory during a six month period. Discuss advantages and limitations of carrying out mesocosm investigations. [3]

a. scientist can alter/manipulate/control environmental conditions b. allows carrying out experiments with many samples / replicates c. ease of collection of continuous data Limitations of mesocosm experiments: d. difficult to mimic natural environmental conditions exactly e. Natural environments change /are not static Needs to suggest advantage and limitation for full marks.

Native oyster populations are decreasing where rivers meet the ocean along the northwest coast of North America. These oyster populations are being attacked by a gastropod. It is known that oysters and gastropods have hard parts composed of calcium carbonate and that ocean acidification is increasing. Studies were carried out using juvenile oysters and gastropods to investigate the effects of acidification on the decrease in the population of oysters. The first step was to raise oysters in two different mesocosms. One had seawater at a normal concentration of CO2 and the other had sea water with a high concentration of CO2. Gastropods were raised in two further mesocosms with normal and high CO2 concentrations respectively. A juvenile gastropod will attack a juvenile oyster by using its tongue-like structure (radula) to drill a hole through the oyster shell. Once the hole has been drilled, the gastropod sucks out the soft flesh. Researchers investigated the shell thickness at the site of the drill hole in relation to the size of the oyster. The results are seen in this graph. Equal numbers of oysters raised in seawater with a normal CO2 concentration and in seawater with a high CO2 concentration were then presented together to the gastropod predators in seawater with a normal CO2 concentration. The same numbers of oysters from the two groups were also presented together to the gastropods in seawater with a high CO2 concentration. The bar charts show how many of the oysters were drilled by the gastropods and the mean size of drilled oysters. The radula in a gastropod is hard but not made of calcium carbonate. Outline how this statement is supported by the drilling success of the gastropods in seawater with normal or high CO2 concentrations.

a. significant factor: concentration of CO2 in which oysters were raised b. insignificant factor: concentration of CO2 at which oysters were presented to gastropods

Coral reefs are among the most spectacular ecosystems on Earth. They support a rich diversity of life and provide economic benefits to the people who use them. In Papua New Guinea in the Pacific Ocean north of Australia the following data were collected. Coral cover is the percentage of the reef surface covered by live hard coral. In order to test the effect of temperature, live samples of a species of coral, Pocillopora damicornis, were placed in an experimental chamber at a constant pH, water depth and low light. All the coral samples were started at 26°C and half of them were rapidly increased to 30°C. The pie charts show the percentage of live and dead tissues at the end of the experiment. Acidification of the world's oceans is an increasing threat to the health of oceanic life including coral reefs. Corals perform calcification to create their calcium carbonate exteriors. An experiment was conducted on Heron Island, Southern Great Barrier Reef, Australia. For the experiment the pH was altered by dissolving carbon dioxide in the water. Three different coral species were used, with each test group at two different temperature ranges and three different pH values. The white line in each photograph represents 5 cm. Comment on whether the experimental data supports the observed data from the ocean.

a. supports because there is more dead coral/less % cover at the higher temperature b. (experimental data) does not support (observed data) because experimental temperatures were (all) higher/rose much faster The answer must make it clear whether or not the data provides support.

Migrating birds must refuel along the way in order to continue flying. A field study was conducted among four different species of migrating birds known to stop at high quality and low quality food sites. Two techniques were used to assess food quality in the stopover sites. Birds were captured and weighed at the two sites. Blood samples were taken from the birds to determine nutrient levels in their blood. The two techniques were compared for their effectiveness. The table below shows data collected from the two sites during one season. A method was used to determine the average mass change in grams per hour (gh-1 ) during the study. Graph A represents a summary of data collected during one season whereas Graph B represents a summary of data collected over 17 years. Among birds, high triglyceride concentration in blood plasma indicates fat deposition whereas high butyrate concentration in blood plasma indicates fat utilization and fasting. The following data summarizes triglyceride levels and butyrate levels measured for the same groups of birds. Suggest one advantage and one disadvantage for blood sampling rather than weighing birds to assess food quality at stopover sites.

advantage: need to capture bird only once to get data / no need to mark and catch birds again; more informative data can be gathered; (do not accept unqualified "more precise") disadvantage: removal of blood is more stressful/risky for the bird than weighing; danger of infection / spread of disease / harm to birds; extra time/money/laboratory equipment is needed to analyse results; could include fat/triglyceride/butyrate from previous/long-term feeding; nutrients from food eaten at these sites may not have been absorbed yet

Define saprotroph.

an organism that lives on/in non-living/dead (organic) matter and secretes digestive enzymes/digestive juices into it / OWTTE

Distinguish between autotrophs and heterotrophs.

autotrophs make their own food/organic molecules/organic matter and heterotrophs feed on/obtain their food/organic molecules from other organisms; autotrophs use/require inorganic molecules/CO2 and heterotrophs require (complex) organic molecules;

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Suggest a reason why the incidence of malaria is so low in the Belize District.

drier climate/less rainfall / more predators / vegetation/ecology not favourable to mosquitoes / higher rainfall so faster flowing rivers/more educated inhabitants so more aware of dangers.

Describe the movement of energy and nutrients in an ecosystem.

ecosystem is a community and its abiotic environment; solar energy collected by autotrophs/plants (via photosynthesis); moves through trophic levels via food; only 5 to 20% transferred from one trophic level to next / never 100% efficient; lost as metabolic heat/organic waste; energy flow can be illustrated by pyramid shape;organisms absorb nutrients from food/environment; nutrients occur as complex organic matter in living organisms; after death, saprotrophic bacteria and fungi (decomposers) breakdown complex organic matter; breakdown products are simpler substances; absorbed into plants for resynthesis into complex organic matter/recycled;

Explain the shape of the pyramids of energy that are constructed by ecologists to represent energy flow in an ecosystem. [3]

energy flows up from one trophic level to the next (in a community); energy is lost at each stage by waste products/feces/not all the organism is consumed; most energy is lost through respiration/heat; each level on the pyramid is about 10% - 20% of the size of the one below it / 80% - 90% energy lost between levels; labelled diagram of pyramid of energy (indicating trophic levels);

Distinguish between the movement of energy and nutrients in an ecosystem. [2]

energy moves through/enters and leaves ecosystems / need a constant source of energy; nutrients cycled between biotic and abiotic environment/in cycles such as C/N;

Explain why the carnivores in an ecosystem tend to be fewer in number and have a smaller biomass than the herbivores in the same ecosystem.

energy transfer along the food chain is less than 100 % efficient;10 % energy transfer between trophic levels;nutrient transfer is less than 100 % efficient;each carnivore needs to consume many prey organisms;tendency for size of organisms to increase as trophic level increases;

identify a food chain with four or more organisms from the forest food web.

example from the food web with four or more organisms, given in proper sequence with arrows showing flow of energy in the correct direction and starting with a producer.

Explain the role of limiting factors in photosynthesis. [8]

factor nearest its minimum/furthest from its optimum is limiting; increasing a limiting factor with other factors constant increases the rate; increasing a non-limiting factor with other factors constant has no effect on rate; light intensity is limiting in dim/low intensity light / at night; photosynthesis (directly) proportional to intensity up to plateau / graph to show this; light intensity affects the light-dependent reactions/production of ATP/NADPH; temperature limiting at low and high temperatures; optimum temperature with lower rates above and below plateau / graph to show this; low temperatures limit the rate of light-independent reactions/Calvin cycle;RuBP carboxylase/rubisco does not fix carbon dioxide at high temperatures; carbon dioxide concentration is limiting in bright light and warm temperatures; photosynthesis is (directly) proportional to CO2 concentration up to plateau / graph to show this;low CO2 concentration limits carbon fixation/reaction between CO2 and RuBP;

Define habitat, population, community and ecosystem.

habitat:the environment in which a species normally lives / the location of a living organism / OWTTE; population: a group of organisms of the same species who live in the same/specific area at the same time/interact; (some reference to commonplace and time is required) community: a group of populations/species living and interacting with each other in an area / OWTTE; ecosystem: a community and its abiotic environment / OWTTE;

The greenhouse effect is a naturally occurring process. Explain how radiation of different wavelengths is involved in the greenhouse effect

incoming shorter-wave radiation/UV/visible passes through Earth's atmosphere; converted to longer-wave radiation/heat/infrared; atmosphere absorbs/traps longer-wave radiation/infrared/heat; Answers can be given in the form of an annotated diagram. Answers must specify long wave/infrared/heat and short wave radiation.

A colony of a marine diving bird, Brunnich's guillemot (Uria lomvia), lives on the southern limits of the Arctic on Coats Island. Brunnich's guillemots feed principally on Arctic cod (Arctogadus glacialis) which are characteristic of Arctic waters. The graph shows the changes in ice cover on Coats Island over a period of 19 years. At Coats Island, chick mass at 14 days was measured in most years between 1988 and 2002. The scattergraph below shows the results, plotted against proportion of ice cover. outline the relationship between ice cover and the mass of 14-day-old chicks on Coats Island. [2]

increase in summer ice cover has a positive effect on mass increase; high proportion of ice cover has little effect / (slightly) negative effect on chick mass/growth;

The enhanced greenhouse effect can cause a rise in atmospheric temperature. Outline two consequences of a global temperature rise on arctic ecosystems.

increased rates of decomposition (of detritus in permafrost); expansion of the range of habitats available to temperate species; loss of ice habitat; changes in distribution of prey species affecting higher trophic levels; increased success of pest species/pathogens; rise in sea levels;

Outline the consequences of a global temperature rise on arctic ecosystems.

increasing rates of decomposition of detritus previously trapped in permafrost; expansion of the range of habitats available to temperate species; loss of ice habitat; changes in water salinity; changes in distribution of prey species affecting higher trophic levels; increased success of pest species;loss of ice increases absorption of solar radiation increasing warming of atmosphere; extinction of species adapted to arctic/cold conditions; humans can/should take steps to reduce/slow losses in habitat / given example of measure taken; statement applying the precautionary principle to this issue;

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Suggest a reason for the decreases in the incidence of malaria from 1995 to 1999.

insecticides used to kill mosquitoes / more anti malarial drugs / drought/less water for mosquito breeding / increased drainage / improved education / more mosquito nets / other reasonable change in conditions

What are the units of a pyramid of energy?

kJ m-2 yr-1

more evenly distributed in summer than in winter (across latitudes); many near Cape Hatteras/35.0/2-35.4/6°N in winter/more than in summer; more dolphins overall in the survey area in winter than in summer; wider summer range / reaches 36.6 and 34.2°N/ less far N and S in winter; unimodal distribution in winter versus bimodal in summer / OWTTE;

Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium. Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mosquito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and are flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period. Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people. The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of malaria. The dark grey bars indicate the total area within each ecosystem with the highest incidence of malaria. The total area with an intermediate incidence of malaria is not shown. Besides farmland, identify which two ecosystems have the greatest total area with a high incidence of malaria.

lowland broadleaf forest and broadleaf hill forests (both required)

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Outline the relationship between body mass and LCTw for male dolphins.

male dolphin with the lowest body mass has the highest LCTw; with larger dolphins/above 180/185/187 kg no change in LCTw with body mass; weak negative correlation / as mass increases LCTw drops / vice versa;uncertainty due to small amount of data;

A colony of a marine diving bird, Brunnich's guillemot (Uria lomvia), lives on the southern limits of the Arctic on Coats Island. Brunnich's guillemots feed principally on Arctic cod (Arctogadus glacialis) which are characteristic of Arctic waters. The graph shows the changes in ice cover on Coats Island over a period of 19 years. At Coats Island, chick mass at 14 days was measured in most years between 1988 and 2002. The scattergraph below shows the results, plotted against proportion of ice cover. Predict, with a reason, the change in the mass of chicks in the years ahead.

mass may go down as proportion of ice cover has decreased; mass may increase as most recent data shown in (bar) graph shows increasing proportion of ice area;

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below Explain how an increase in water temperature due to global warming could affect the distribution of bottlenose dolphins along the eastern coast of the USA.

may migrate/move range further north;migrate to area with cooler/suitable water temperature; ocean currents may change; most productive waters/food supply may be further north; distribution more spread out (due to warmer waters in more areas);

Explain why carnivores tend to be more affected by biomagnification than organisms lower down the food chain.

mercury / DDT / other named example; biomagnification is the accumulation of chemicals through the food chain; chemicals that undergo biomagnification are stored/not broken down (in the bodies of the organisms that consume them); chemicals are passed (unaltered) from one trophic level to the next; chemicals become more concentrated in the bodies of each (subsequent) trophic level; organisms higher up the food chain consume larger amounts of the chemical;

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Compare the distribution of dolphins in summer and winter.

more evenly distributed in summer than in winter (across latitudes); many near Cape Hatteras/35.0/2-35.4/6 °N in winter/more than in summer; more dolphins overall in the survey area in winter than in summer; wider summer range / reaches 36.6 and 34.2 °N/ less far N and S in winter; unimodal distribution in winter versus bimodal in summer / OWTTE;

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Compare the data for the dolphin populations in winter and summer.

more surveys in summer / fewer in winter; larger average/biggest number sighted (per survey) in winter / converse; larger total number of dolphins (from adding up all surveys) in summer; variation in both seasons / overlap in numbers between summer and winter; Do not accept answers relating to distribution. Do not accept answers stating that the dolphin population is higher in winter.

State one reason that the population of mountain lions is smaller than the populations of other animals in the food web.

mountain lions/highest trophic level receives less energy as energy is lost at each level / mountain lions are larger than other animals and require more (smaller) individuals for food.

The graph below shows the monthly mean values of terrestrial invertebrates from May 1997 to June 1998 in the northern hemisphere. The light line shows the biomass of invertebrates which are prey to forest birds (terrestrial invertebrate biomass). The darker line shows the invertebrates which lived in the stream and have moved to the forest (aquatic invertebrate flux or movement). The black bars on the horizontal line at the bottom show periods when trees have leaves and the white bars show periods of defoliation. Suggest the relationship between defoliation and the amount of terrestrial invertebrates in the forest.

negative relationship / during period of defoliation, biomass (of terrestrial invertebrates) is at its lowest; less leaves means less food/habitats / easier for predators to see invertebrates; defoliation occurs in winter/autumn and the cold may kill invertebrates;

The graph below shows the monthly mean values of terrestrial invertebrates from May 1997 to June 1998 in the northern hemisphere. The light line shows the biomass of invertebrates which are prey to forest birds (terrestrial invertebrate biomass). The darker line shows the invertebrates which lived in the stream and have moved to the forest (aquatic invertebrate flux or movement). The black bars on the horizontal line at the bottom show periods when trees have leaves and the white bars show periods of defoliation. Suggest the relationship between defoliation and the amount of terrestrial invertebrates in the forest. [2]

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below Suggest one reason for the high LCTw measured for the female dolphin.

older so (possibly) has a lower metabolic rate / other result of age; higher surface area to volume ratio (than male); less active than males so releasing less metabolic heat; less insulation due to subcutaneous fat/adipose tissue; suckling / pregnant / part of mass was fetus;

Explain the principles involved in the generation of methane from biomass. [3]

organic matter/manure/waste/agricultural material/seaweed used; bacteria in digester transform biomass/raw material; anaerobic conditions / constant temperature / neutral pH in the digester; bacteria convert organic material to organic acids/alcohol; other bacteria convert organic acids/alcohols into acetate; methanogenic bacteria convert acetate to methane

What is a community composed of?

populations

The graph below shows the monthly mean values of terrestrial invertebrates from May 1997 to June 1998 in the northern hemisphere. The light line shows the biomass of invertebrates which are prey to forest birds (terrestrial invertebrate biomass). The darker line shows the invertebrates which lived in the stream and have moved to the forest (aquatic invertebrate flux or movement). The black bars on the horizontal line at the bottom show periods when trees have leaves and the white bars show periods of defoliation. Describe the trend in the aquatic invertebrate flux.

rapid rise and fall between April and August; peak in May/June;fluctuates between August/September and December;l ow December/January until February/March; cyclical;

Outline two possible consequences of global warming for organisms living in arctic ecosystems.

reduced space/habitat (for ice-dwelling species) / valid example; increased competition (from temperate species); arctic species forced to migrate (in search of suitable habitats/food); changes in patterns of (seasonal) migration; extinction of some species due to inability to adapt quickly/compete successfully; increased activity of decomposers; increased success of pest species including pathogens; changes in the distribution of prey species;

Migrating birds must refuel along the way in order to continue flying. A field study was conducted among four different species of migrating birds known to stop at high quality and low quality food sites. Two techniques were used to assess food quality in the stopover sites. Birds were captured and weighed at the two sites. Blood samples were taken from the birds to determine nutrient levels in their blood. The two techniques were compared for their effectiveness. The table below shows data collected from the two sites during one season. A method was used to determine the average mass change in grams per hour (gh-1 ) during the study. Graph A represents a summary of data collected during one season whereas Graph B represents a summary of data collected over 17 years. Among birds, high triglyceride concentration in blood plasma indicates fat deposition whereas high butyrate concentration in blood plasma indicates fat utilization and fasting. The following data summarizes triglyceride levels and butyrate levels measured for the same groups of birds. Explain the differences in the triglyceride level and butyrate level for the hermit thrush at Site 1 and Site 2.

riglyceride higher at Site 1 because more fat deposition / HT eats more; butyrate higher at Site 2 because more fat/triglyceride utilized / HT fasts more;

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below. Suggest one reason for the differences in distribution.

seasonal variation in food supply/prey/predators/water temperatures; migration to find food/prey/warmer water/mates; migrating dolphins rest/congregate near Cape Hatteras/35.2 - 35.4°N; Cape Hatteras /35.2 - 35.4°N may be a mating area in the winter; seasonal variation in human activity / valid example; more food/warm water between mainland and Cape Hatteras in winter;

seasonal variation in food supply/prey/predators/water temperatures; migration to find food/prey/warmer water/mates; migrating dolphins rest/congregate near Cape Hatteras/35.2 - 35.4°N; Cape Hatteras/35.2 - 35.4°N may be a mating area in the winter; seasonal variation in human activity / valid example; more food/warm water between mainland and Cape Hatteras in winter;

Bottlenose dolphins (Tursiops truncatus) inhabit almost all tropical and temperate oceans between 45°N and 45°S. Over a two-year period, aerial surveys were carried out to investigate the seasonal distribution of these animals along the mid-Atlantic and eastern coastal waters of the USA. Sightings were recorded using a global positioning system (GPS) while flying in a regular pattern within approximately 65 km of the shore. A total of 12 760 dolphins were sighted over the two-year period and the data are summarized in the chart below. Each bar corresponds to a single survey and the length of the bar corresponds to the total number of bottlenose dolphins counted in that survey. The circles with numbers indicate numbers of dolphins. As part of the same study, coastal aerial surveys were carried out over the same time period by flying parallel to the coast approximately 500 m offshore. The diagram below shows a map of the section of coast surveyed. The bar graph shows the seasonal data for summer and winter at the corresponding latitudes (°N). A total of 5431 bottlenose dolphins were sighted during these surveys. In a different study, researchers investigated the role of water temperature as a possible factor in the distribution of bottlenose dolphins. The rate of metabolism (measured as the rate of oxygen uptake per unit mass) of five captive adults was measured under a range of water temperatures. The rate of metabolism was found to increase significantly when the water temperature fell below a certain value known as the lowest critical water temperature (LCTw). Below this temperature the body uses more energy to combat the cooling effect of the surrounding water. The data for these animals are summarized below Evaluate the hypothesis that water temperature determines the range and distribution of bottlenose dolphins in the wild.

supported as water temperature affects metabolic rate; supported as dolphins will avoid areas with water below their LCTw; water temperature is unlikely to be a factor for bigger males; wide (latitude) range in summer suggests temperature does not determine range; few animals / only one female / only narrow range of latitudes investigated; data may not be reliable since the study was conducted in captivity;

Male Lepidoptera (butterflies and moths) commonly drink from pools of water or from moist soil. This behaviour, called puddling, was investigated in an undisturbed area where male tiger swallowtails, Papilio glaucus, had been seen puddling. Four successive sets of experiments were performed under similar conditions of temperature and humidity. In each set, equal samples of sand were spread out evenly on trays and then treated differently. Except for one dry sample (in the first set), all others were saturated with a different liquid. Results of the observations are given in the table below. Male Lepidoptera (butterflies and moths) commonly drink from pools of water or from moist soil. This behaviour, called puddling, was investigated in an undisturbed area where male tiger swallowtails, Papilio glaucus, had been seen puddling. Four successive sets of experiments were performed under similar conditions of temperature and humidity. In each set, equal samples of sand were spread out evenly on trays and then treated differently. Except for one dry sample (in the first set), all others were saturated with a different liquid. Results of the observations are given in the table below. Discuss the relationship between sampling visits (V) and puddling time (T) in experiments 1, 2 and 3.

unclear correlation between V and T; depends on the nature of the substrate and its concentration; sometimes high V with low T (e.g. experiment 1 for sucrose) / sometimes high V with high T (e.g. experiment 2 for NaCl);

सभी स्टडी सेट्स देखें

FIRE 305 Ch. 5-8, FIRE 305 Ch. 1-4, Chapter 11, Chapter 10, Chapter 9, Chapter 8, Chapter 7, Chapter 6, Chapter 5, Chapter 4, Chapter 2, Chapter 3, Chapter 1

Ecology Study

संबंधित स्टडी सेट्स

FIRE 305 Ch. 5-8, FIRE 305 Ch. 1-4, Chapter 11, Chapter 10, Chapter 9, Chapter 8, Chapter 7, Chapter 6, Chapter 5, Chapter 4, Chapter 2, Chapter 3, Chapter 1

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