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Flashcards in Humans And Their Environment Deck (15):

How may waste pollute water?

With sewage, fertiliser or toxic chemicals.


How may waste pollute air?

With smoke and gases such as sulphur dioxide which contributes to acid rain.


How may waste pollute land?

With toxic chemicals such as pesticides and herbicides, which may be washed from the land into waterways.


How do humans reduce the amount of land available for other animals and plants?

By building, quarrying, farming and dumping waste.


Large scale deforestation in tropical areas, for timber and to provide land for agriculture, has:

1. Increased the release of carbon dioxide into the atmosphere (because of burning and the activities of microorganisms)

2. Reduced the rate at which carbon dioxide is removed from the atmosphere and 'locked up' for many years as wood.


What does deforestation lead to?

Reduction in biodiversity.


Give 2 reasons why deforestation has occurred.

1. Crops can be grown from which biofuels, based on ethanol, can be produced.

2. There can be increases in cattle and in rice fields to provide more food. These organisms produce methane and this has led to increases in methane in the atmosphere.


What does the destruction of peat bogs release?

Carbon dioxide


What are possible effects of global warming?

1. May cause big changes in the earths climate
2. May cause a rise in sea level
3. May reduce biodiversity
4. May cause changes in migration patterns
5. May result in changes in the distribution of species


How can biofuels be made?

From natural products by fermentation.


How can biogas (mainly methane) be produced?

By anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates.


What 2 ways can improve the efficiency of food production?

1. By reducing the number of stages in food chains.

2. By restricting energy loss from food animals by limiting their movement and by controlling the temperature of their surroundings.


Give an example of sustainable food production.

Fish sticks in the oceans are declining, it's important to maintain fish stock at a level where breeding continues therefore net size and fish quotas play an important role in conservation of fish stocks.


How is the fungus fusarium useful?

For producing mycoprotein, a protein-rich food suitable for vegetarians.


How is the fungus Fusarium grown?

The fungus is grown on glucose syrup, in aerobic conditions, and the biomass is harvested and purified.