B3.4

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  • Created by: ellaj03
  • Created on: 30-01-17 18:02
Why is the human population growing so rapidly? (2)
Modern medicine and farming is preventing death from disease and hunger.
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What are the three types of pollution? Give examples
Water - Sewage and toxic chemicals pollute rivers, as do fertilisers. Land - Toxic farming chemicals and landfill waste are affecting our land. Air - smoke and gases released into the atmosphere pollute the air.
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How are we reducing the land available for plants and animals?
Buildings, farming, dumping waste and quarrying.
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What is a greenhouse gas? (give examples)
A gas that contributes to the greenhouse effect as it absorbs infrared radiation. Water vapour, carbon dioxide, methane and nitrous oxide.
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What are the natural stores of Carbon Dioxide? (3)
Water (oceans, lakes and ponds), green plants and peat bogs.
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How is Carbon Dioxide produced?
By the burning of fossil fuels.
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What are the four main problems as a result of deforestation?
More methane in the atmosphere (cattle and rice), more Carbon Dioxide in the atmosphere, less carbon dioxide taken in and less biodiversity.
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What is the greenhouse effect?
The greenhouse effect is when the gases in the atmosphere act as an insulating layer of air around the earth. They absorb most of the heat that otherwise would have radiated out into space and the re-radiate it in all directions including back to ear
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Why is the greenhouse effect becoming an issue?
The amount of greenhouse gases in the atmosphere has increased so much that too much heat is being radiated back to earth increasing our global temperature.
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What are the effects of an increased global temperature? (6)
Sea gets hot so expands, ice caps melt (rising sea level), change in weather patterns causing more extreme weather, change in distribution of plants and animals, decrease in biodiversity and change in migration patterns.
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What are biofuels?
Fuels produced by plant material, they are carbon neutral.
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Fuels can be made by fermentation, what is fermentation?
Fermenation is when bacteria or yeast break sugars down by anaerobic respiration.
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What is the word equation for the production of ethanol?
Glucose → Ethanol + Carbon Dioxide + Energy
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How is a biogas made?
It is made by anaerobic fermentation of Waste Material.
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Why do we use ethanol or biogas?
Because they are carbon neutral.
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How is biogas made?
Different microorganisms ferment plant and animal waste in a simple fermenter called a digester or generator.
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Why does biogas need to be kept at a constant temperature?
To ensure the the microorganisms keep respiring away.
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Why does biogas have to be used straight away?
Biogas cannot be stored as a liquid (it needs too high a pressure) so it is used instantly for heating, cooking, lighting or to turn a turbine.
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What is a batch generator?
They make biogas in small batches and the waste is manually loaded into the machine with the leftovers being cleared away at the end.
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What is a continuos generator?
Continuos generators make biogas constantly, the waste is continually fed in at a constant rate. They are used for larger scale projects.
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What are the four factors you must consider when designing a generator?
Cost, convenience, efficiency and position.
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What are the advantages of biofuels? (6)
They are carbon neutral, it doesn't produce a lot of sulphur and nitrogen oxides, prevents methane from being released into the atmosphere, it is cheap and readily available, waste product is a good fertiliser and acts as a waste disposal system.
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What increases the efficiency of food production? (3)
Reducing the number of stages in the food chain, restricting energy lost by farm animals and developing new food sources like mycroprotein.
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What is meant by intensive farming?
Intensive farming is when farmers keep animals close together indoors in small pens so they are warm and can't move. This reduces energy needed to maintain body temperature and movement so they grow faster.
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What is Mycroprotein?
Mycroprotein is protein made from fungi which is then used as a meat substitute.
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How is Mycroprotein made?
A fungus called Fusarium is grown in fermenters using glucose syrup as food. It is harvested then purified.
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What are the advantages of Mycroprotein?
It is quick, doesn't require a lot of space and can use waste materials in production.
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How do you reduce the number of stages in the food chain?
You can produce a lot more food by growing crops instead of having grazing animals as there is one less stage in the food chain.
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Why does food distribution cause problems?
When food has been transported a long way the vehicles it travels on often contribute to global warming or carbon dioxide emission.
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What does overfishing cause?
It causes a decrease in fish stocks.
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What two ways can fish stocks be conserved?
By fishing quotas or different net sizes.
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What is a fishing quota?
The maximum number of fish each boat can fish per year.
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How does net size help conserve fish stocks?
The holes in nets are made bigger so baby fish can escape, live their lives and reproduce.
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Other cards in this set

Card 2

Front

What are the three types of pollution? Give examples

Back

Water - Sewage and toxic chemicals pollute rivers, as do fertilisers. Land - Toxic farming chemicals and landfill waste are affecting our land. Air - smoke and gases released into the atmosphere pollute the air.

Card 3

Front

How are we reducing the land available for plants and animals?

Back

Preview of the front of card 3

Card 4

Front

What is a greenhouse gas? (give examples)

Back

Preview of the front of card 4

Card 5

Front

What are the natural stores of Carbon Dioxide? (3)

Back

Preview of the front of card 5
View more cards

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