Biology 3 Unit 4
Card Set Information
Biology 3 Unit 4
How humans affect the environment
How do human pollute water?
Humans pollute water with:
Causing high level of nitrates in the water
How do humans pollute the air?
Humans pollute the air with:
Smoke and gasses such as sulphur dioxide, which contributes to acid rain
How do humans pollute land?
Humans pollute land with:
Toxic chemicals such as pesticides and herbicides, which may be washed away into the water
What is the effect of large scale deforestation?
Increased the release of carbon dioxide into the atmosphere
Reduces the rate at which carbon dioxide is removed from the atmosphere, by photosynthesis
Reduces biodiversity due to loss of food and habitat
Why has deforestation occurred?
Deforestation has occurred so that:
Crops can be grown to produce ethanol-based biofuels
There can be an increase in cattle and rice fields to provide more food
What is the disadvantage of the increase production of cattle and rice fields?
Cattle and rice growing produce methane, which has led to an increase of methane in the atmosphere
Why is the destruction of peat bogs bad?
The destruction of peat bogs and other area of peat result in the release of carbon dioxide into the atmosphere; due to the decay of the compost by micro organisms
How is carbon dioxide sequestered?
Carbon dioxide is sequestered as carbon dioxide is removed from the air by plants and by dissolving in oceans, rivers and lakes
What is meant by greenhouse gasses?
This is the level of carbon dioxide and methane increasing in the atmosphere
What will happen if there is a slight increase in the earths temperature?
An increase in the earths temperature may:
Cause big changes in the earths climate
Cause rise in sea levels
Cause change in migration patterns eg. Birds
Changes in the distribution of species
Describe the process of ethanol-based fuels?
Ethanol-based fuels can be produced by fermentation
Glucose is produced from maize starch by the action of carbohydrase
Microorganisms (yeast) respire anaerobically to produce the ethanol, using sugars from crops as the energy
Ethanol is extracted by distillation
How can the efficiency of food production be improved?
The efficiency of food production can be improved by reducing the number of stages in food chains
How can we produce meat more efficiently?
We can produce meat more efficiently by:
Preventing the animals from moving so energy isn't wasted on movement
Controlling the temperature of their surroundings so that energy from food isn't wasted to maintain body temperature
What is meant by sustainable food production?
This is a method of producing food which can be sustained over time without destroying the fertility of the land or ocean
How are fish stocks in the ocean monitored?
Fishermen can only remove a strict allocation of fish per year
Fishermen must use certain sized nets to avoid catching small, young fish.
What is mycoprotein?
Protein from fungus
What is Fusarium?
Fusarium is grown to produce mycoprotein.
This is a protein-rich food suitable for vegetarians
How is Fusarium grown?
The fungus is grown aerobically on cheap sugar syrup and the biomass is harvested and purified
What factors must be controlled in large industrial fermenters?