Unit 4 keywords

All key words we need to know for unit 4 environmental science.

  • Created by: Dotty
  • Created on: 25-05-11 09:41

The population: resource balance

The Population: resource balance.

Affluence: the level of richness or poverty.

Per Capita: per person, such as the per capita of resources or waste production.

Altruism: acting for the benefit of all or others.

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Pasture: land used for grazing livestock.

Pesticide: chemical used to kill pest species.

Sustainable: an activity that can be carried out without depleting resources and takes the future into consideration.

Photoautotroph: organism that produces high-energy food substances using light. eg photosynthetic organisms.

Food chain: sequence of organisms arranged to show their feeding relationships and food energy flow. Primary producer...etc

Trophic level: a position in a food chain.

Herbivore: plant eating animal.

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Agriculture continued

Genetic engineering: the method of altering an organims genetic makeup by artificially introducing genes from another organism/species.


Transgenics: process of artificially transferring genetic material from one organism into an individual of another speices. 

Horizontal gene transfer: transfer of genetic material between organisms withought normal breeding taking place.

Auxin: a group of plant hormones.

Gibberelin: a group of plant hormones.

Ethylene: chemical that stimulates fruit ripening.

BST: an animal hormone used to stimulate milk production.

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Agriculture continued...

Rumen: the stomach chamber in which bacteria digest cellulose in ruminants. eg cows and sheep.

Vegetative propagation: asexual reproduction.

Cloning: an artificial form of asexual reproduction.

Crossbreeding: production of offspring by mating parents of two different breeds or varieties.

Hybrid vigour: the good health achieved by breeding between breeds that are not closely related. Reducing the risk of inbreeding and recessive gene disease.

Carnivore: organisms that gains food energy from other heterotrophs.

Omnivore: and animal that eats both meat and plant. eg pig. 

Tenant farmer: a farmer that rents land from the owner.

Quota: a limit on the number or quantity of items.

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Agriculture continued...

Haber process: a chemical process used to manufacture ammonia from which nitrate fertilisers can be made.

F1 hybrid: first generation of offspring produced by breeding from two distinct true-breeding varieties. All offspring have the same combinations of characteristics.

True-breeding variety: variety of selectively bred organism where all members are almost genetically identical and produce similar offspring.

 Asexual reproduction: production of new organims using the gentic material from a single individual.

Heterosis: the hybrid vigour produced by breeding between two organisms that are not closely related.

IR8: a green revolution rice variety.

Green Revolution: agricultural changes since mid 20th century, where high yeilding cereal varieties were bred to increase food production.

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agriculture continued.....

Anabolic steroid hormones: a hormone used to increase livestock gross growth efficiency.

Endemic pest: a pest that is normally present.

Epidemic pest: a pest that is not normally a problem but may become a serious pest when the population suddenly increases.

Monoculture: the growth of a single type of crop, usually over a large area.

Liposoluble: property of a substance dissolving in lipids.

Organochlorine pesticides: persistent insecticide group, eg DDT.

Systemic: a substance that is absorbed and transported throughout an organism.

Organophosphate pesticides: insecticide group, eg parathion.

Pyrethroid pesticides: insecticide group.

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Agriculture continued further....

Zoonose: a micro-organism that is carried by livestock which, if transferred to humans, causes disease.

 Crop rotation: the practice of growing a different crop in a field on a cycle of three, four or five years.

Mulch: material added  to the soil surface.

Pheromone: a chemical released by an organism that changes the behaviour of other members of the same species, especially to attract a mate.

Humus: the colloidal material in the soil that is the end product of the decomposition of dead organic matter.

Macronutrient: a plant nutrient needed in large quantities.

Micronutrient: a plant nutrient needed in small quantities.


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Last of the agriculture

Extensive agriculture: where the maximum total yield is achieved by distributing the inputs over the total available area, inputs are usually low.

Intensive agriculture: where high yields are achieved by using large inputs per unit area.

USLE:universal soil loss equation.

Tillage: cultivation by turning the soil.

Marshall plan: a US scheme after WW2 to provide food aid to europe.

Set aside: farmland that has been taken out of production and is not cultivated but is kept in a condition where it could be farmed again.

ESA: environmentally sensitive areas.

Countryside stewardship scheme: a scheme where farmers could get grants for a range of activities that benefited the environment or improved amenity value for the public.

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Aquatic food production Systems

ESS: environmental stewardship scheme.

Aquatic food production systems

Crustaceans: group of invertebrates with joined limbs and an exoskeleton, eg crab and lobsters.

Molluscs: invertebrates with a hard shell, eg clams and oysters.

Algae: primitive photosynthetic plant-like organisms.

Phytoplanktonic: free-floating photosynthetic organisms that drift with the waters currents.

Algal blooms: the rapid growth of an algae population.

Photic layer: the layer of water into which sunlight can penetrate.

Maximum sustainable yield: the greatest amount that can be sustainably harvested.

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Aquatic food production systems

Overfishing: fishing above the maximum sustainable yield.

Pelagic: living near the water surface, eg tuna.

Demersal: living on the seabed eg cod.

Bycatch: non target organisms that are caught when fishing.

Aquaculture: artifical production of aquatic organisms including fish farming.



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Climax community: community of organims at the end of primary succession.

Taiga: northern conifer forest biome found in canada, scandinavia and russia.

Conifers: trees that produce their seeds in cones.

Stomata: pores on a leaf through which gases are exchanged and transiration water is lost.

Temperate: a temperate climate has summers and winter of roughly equal length and rarely has temperature extremes.

Deciduous: the process of shedding all leaves at the same time.

Understorey: layer of tree vegetation beneath the canopy layer.


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Forestry continued..

Tropical: the region of the earth within 22.5 degrees of the equator where the sun is overhead at some time during the day.

Primary productivity: the energy campured during photosynthesis.

Canopy: uppermost layer of vegetation in a forest.

Stratification: layering, as seen with layering in forests.

NPP: net primary productivity- the energy captured by an autrotroph during photosynthesis but which has not been used in respiration.

Coppicing: the process where trees are cut to ground level every few years.

Pollarding: the process whereby trees are cut back to 4-8ft above the ground every few years.

Forest parks: forestry commission forest areas that are open to the public for recreational use.

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Forestry continued...

National forest: an area in the east midlands of england where woodland creation and countryside managment is being carried out for the benefit of the local communities and wildlife.

Community forest: a deliberately managed and planted forest for the benefit of the community.

Programme for Belize: independent conservation organisation that manages the Rio Bravo Conservation and management area in Belize, Central America.

Forestry Stewardship Council: an organisation that certifies sustainable forestry operations.


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Planned obsolescence: the deliberate plan to make items that do not last as long as they could have.

Ecological Footprint: the area of the earths surface needed to provide the resources that are used byt he human population and to deal with the waste products.

Ecological debt: concept that we are exploiting the planet at a faster rate than it can replace the resources we have used.

Ecological Debt day: the day on which it is estimated that we have used up the whole years worth of resources.

Carbon footprint: part of the ecological footprint caused byt he release of carbon dioxide and other greenhouse gases.

Biocapacity: measure of the biological productivity of an area.

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Joshua Murray


On Page 10, 'Demersal' is living near the sea bed, on the sea bed is 'Benthic'.

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