standard Grade Biology - topic one : Biosphere

  • Created by: Bethany
  • Created on: 08-10-11 16:14

Control and Management 

Pollutantssubstances that have an adverse effect on the environment

Toxica word meaning much the same as poisonous

Radiation high energy waves from nuclear fuels that cause damage to cells

Organic a substance that has come from a living organism

Species a group of organisms that can interbreed and produce fertile offspring

Insecticides chemicals used to kill insects that reduce the yield of crops

Herbicides chemicals used to kill weeds that compete with the crop plants

Fungicides chemicals used to kill fungi that can damage seeds and leaves

Sources of pollution  Pollution affects the air, the land, fresh water and the sea. You are expected to know that the main sources of pollution are from:

industry - soot, carbon dioxide, sulphur dioxide, oxides of nitrogen, oil, heavy metals and radiation

agriculture - pesticides, run off from silage, excess fertilisers and slurry

households - sewage, detergents, litter and domestic waste

Modern society requires increasing use of energy, but there are drawbacks associated with both of the main ways in which energy is produced. These areburning fossil fuel reserves (coal, gas and oil) and from nuclear power.

Burning fossil fuels creates soot and smogs which restrict photosynthesis in plants and coats the environment with grime. In addition sulphur dioxide and carbon dioxide are produced. These lead to acid rain and global warming. We are also using up resources which can never be replaced.

The main alternative is nuclear power which carries a risk of dangerous leaks of radiation at high levels and involves the constant release of low level radiation in the cooling water from power stations. Radiation is known to increase the risk of cancer. The used fuel has to be stored and the long term effects of storing highly radioactive materials are unknown.

examples of how pollution can be controlled :

legislation by parliament, for example the Clean Air Acts

European agreements to decrease sulphur dioxide emissions

world agreements to reduce carbon dioxide production

removal of sulphur and nitrogen oxides from flue gases from power station chimneys

fitting catalytic converters to car exhausts

use of lead free petrol

treatment of sewage before releasing it into rivers

Effect of sewage on water


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