ESS Review

Topics 1 & 8

100

Which is an example of negative feedback? A. Loss of vegetation leading to soil erosion leading to further loss of vegetation. B. A decline in a large predator population after they have eaten most of their prey population. C. Melting of permafrost in the tundra due to climatic change leading to further release of methane, causing further change. D. Unsustainable slash and burn agriculture practices in tropical rain forests.

B

200

Define "ecological footprint"

area of land and resources required to sustainably provide all resources at the rate at which they are consumed

300

The data below refers to the world population in 1998. Crude birth rate = 23 per thousand Crude death rate = 9 per thousand The Natural Increase Rate was:

1.4

400

Distinguish between the terms renewable and sustainable

“Renewable” resources can be naturally replenished; “Sustainable” is the use of resources at a rate less than or equal to their replenishment / that allows similar use for future generations; “Renewable” refers to the resources themselves; “Sustainable” refers to the activities affecting resources (eg extraction/ exploitation/use); resources may be “renewable” but their current extraction/exploitation/use may, or may not be “sustainable”;

500

Evaluate the use of incineration as an alternative to recycling for the management of solid waste.

PROS cheaper/costs; reduces amount of waste more quickly than recycling; ash may be used as a raw material (e.g. road building); can deal with waste that cannot be recycled; can kill disease agents; can reduce the toxicity of waste; can produce energy; CONS residues still require disposal; ash from combustion can be toxic; may produce undesirable air pollutants (such as carbon dioxide/GHGs/linked to health problems); transportation concerns/costs; capacity limitations; reluctance of some owners/operators/residents; it does not reduce resource use as recycling does;

Topic 2

100

Net Primary Production is the amount of energy A. produced from ‘alternative’ sources in developing countries. B. fixed in an ecosystem by photosynthesis. C. fixed in an ecosystem by photosynthesis, minus the losses due to respiration by producer organisms. D. fixed by the herbivores in an ecosystem.

C

200

Define "bioaccumulation"

build-up of persistent or non-biodegradable pollutants within an organism or trophic level because they cannot be broken down

300

To estimate the population of animal S, the students marked the eight individuals that they found and returned them to the ecosystem. One week later, the students caught 20 individuals of animal S, of which five were marked. Estimate the size of the population of animal S.

32

400

Draw 3 flows and the corresponding storages associated with the nitrogen cycle

protein in plants -feeding-> proteins in animals N2/atmospheric nitrogen -nitrogen fixation-> soil nitrogen soil nitrates -denitrification-> N2/atmospheric nitrogen soil nitrites -nitrification-> soil nitrates organisms -death/decomposition-> soil nitrogen soil nitrogen -absorption-> plants

500

Outline the role of limiting factors in S and J population curves.

the initial gradient of both S and J-curves is low due to limiting factors / low numbers reproducing; initially exponential increase / positive feedback occurs in both S and J-curves; in S-curves, limiting factors eventually slow the population growth/maintain equilibrium/plateau (the population has reached its carrying capacity); eg limited food / increased predation/disease / accumulation of wastes / competition; limiting factors may be density dependent / provide negative feedback mechanism to maintain this equilibrium; in J-curves, limiting factors eventually lead to rapid decline/population crash; eg seasonal climate change / disease / overexploited food resources (typically r-selected species); while both S and J curves may be influenced by density independent factors, it is the density-dependent factors that bring about an equilibrium in S-curves;

Topic 3

100

Which statement is correct? A. Elephants are K-strategists because they have a low population growth rate. B. r-strategists tend to reproduce late and have few offspring. C. The population size of a species is only genetically controlled. D. All plants are K-strategists because they have limited ability to compete.

A

200

Define "speciation"

the formation of new species when populations of a species become isolated and evolve differently

300

Calculate the biodiversity of an area in where are: 4 individuals of species A 5 individuals of species B 7 individuals of species C 4 individuals of species D

4.4

400

Name a species of plant or animal that has become extinct since 1600, and list two factors that help to explain why that species became extinct

name of species, e.g. dodo; confined to small island/limited distribution; small population; useful source of food for visiting sailors; extreme tameness; large and conspicuous; slow rate of reproduction; habitat destruction; competition with introduced organisms

500

Describe two factors that may be used to determine a species’ Red List status and how each may be affected by human activity.

population size/reduction in population/numbers of mature individuals/geographic range/fragmentation/quality of habitat/area of occupancy/location prone to natural disaster/species characteristics/probability of extinction deforestation/harvesting/hunting/urbanisation/infrastructure/pollution/trade in rare species/introduction of non-native species/unfavourable climate change due to anthropogenic global warming/conservation/protection management/poor land management/fracking

Topics 4 & 5

100

Which statement about soils is correct? A. Clay soils are capable of retaining more moisture than sandy soils. B. Soils form rapidly in some climates and thus soil is often regarded as a renewable resource. C. Irrigation of soils prevents salinization. D. Loam soils are generally less productive than either clay or sandy soils.

A

200

Define "biotic Index"

indirectly measures pollution by assaying the impact on species within the community according to their tolerance, diversity and relative abundance

300

In a deer population of 1000, each year an average of 100 die from natural causes and 250 are born. Assuming no immigration or emigration, the sustainable yield is...

150

400

Explain how eutrophication illustrates both positive and negative feedback systems

positive feedback as more nutrients are added to the system, biomass of algae increases due to non limiting nutrients; decomposition of increased biomass leads to further nutrient load and so further deviation from equilibrium / positive feedback occurs increase in dead organic matter provides more food for decomposers which increase in number; increased rate of decomposition leads to a decrease in dead organic matter so balance is restored / negative feedback occurs;

500

Outline how soil degradation can be caused by human activities

soil degradation is the loss of fertility/quality of a soil; overgrazing can lead to compaction so soil is more likely to be eroded overcultivation can lead to nutrient depletion/loss of soil structure deforestation/overgrazing can lead to loss of vegetation so soil is more easily dried out/baked by the sun/eroded overgrazing, overcultivation and deforestation can lead to desertification salinization can be caused by excessive irrigation overpopulation forces people to farm marginal areas removal of hedgerows/woodlands / windbreaks can expose soil to erosion;

Topics 6 and 7

100

Which factor greatly increases the likelihood of photochemical smog forming over a city? A. Low altitude B. High rainfall C. High traffic densities D. Short daylight hours

C

200

Define "adaptation"

strategies that attempt to manage the impacts of climate change

300

In March 1979 there was 16.5 million square km of sea ice. In March 2012 there was 7.0 million square km of sea ice. Calculate the percentage change in sea ice cover from March 1979 to March 2012.

7.9% reduction

400

State three reasons why global energy use continues to rise

growth in human population; increase in affluence/wealth; technological developments; increased travel; increased industrialization; increased international trade/globalization;

500

Distinguish between the causes of recent global warming and those of ozone depletion

for GW are CO2/CH4/CFCs (whereas) for OD are halogen containing gases/CFCs/NOx; for GW are human causes are very diverse (whereas) for OD more limited; for GW include burning fossil fuels for transportation/agriculture/deforestation (whereas) for OD refrigeration for GW involves GHGs trapping more infra-red/heat (whereas) OD involves chemical breakdown of ozone molecules; for GW involves increase in mean global temperature (whereas) OD involves more UV passing through atmosphere; GW occurs globally (whereas) OD is concentrated around the poles; OD is caused largely by MEDC activities (whereas) LEDCs make significant contribution to GW through deforestation/rice culture;