| A | B |
|---|
| Population size | Getting bigger at a faster and faster rate |
| Food production | Needs to be increased to keep a larger population alive |
| Waste removal | Needs to be increased to keep a growing population. Perhaps using landfill sites. |
| Energy | Bigger populations need more of this. Providing it using up fossil fuels and causing pollution. |
| Pest control | Biological or chemical destruction of harmful insects |
| Ladybirds | Both adults and larvae eat aphids |
| Parasitic wasps | Their larvae grow inside living caterpillars |
| Biological control | Using predators or parasites to kill harmful insects |
| Insecticide | Chemicals used to kill harmful insects |
| Herbicide | Chemicals used to kill weeds |
| Selective | A chemical which only kills the organisms you want to kill |
| Resistance | What pests develop, faster than we can think of new pesticides |
| DDT | Chemical which was used as a pesticide and is now banned because it builds up in top consumers and kills them too |
| Pollination | A job done by bees. Its a shame pesticides have killed millions of them |
| Fruit | Only made by fruit trees which have been pollinated |
| Acid rain | Caused by sulphur dioxide and nitrogen oxides when they react with water |
| Fish eggs | Don't hatch in acidified lakes |
| Greenhouse effect | Caused by carbon dioxide and methane |
| Limestone | A sedimentary rock, destroyed by acid rain |
| Carbon dioxide | A greenhouse gas absorbed by trees |
| Polar ice caps | Melting, due to the greenhouse effect |
| Gulf stream | An ocean current which may be diverted by the greenhouse effect. The UK would then get colder. |
| Extinction | What will happen to lots of organisms if the climate changes |
| Atmosphere | Where greenhouse gases build up |
| Endangered | Animals which are close to extinction |
| Medicine | Useful chemicals found in many tropical plants |
| Deforestation | What is happening to many tropical forests |
| Logging | Type of organisation which make most money from destroying tropical rainforests |
