Carbon cycle and water cycle

Question 1

Why must materials be recycled?

Answer 1

• There is a finite amount of each element on the planet
• Elements need to be recycled in order to allow new organisms to be made and grow

Question 2

Steps of the water cycle

Answer 2

• The sun heats up water on the Earth’s sruface (can be from rivers, lakes or from the soil), causing it to evaporate and form water vapour
• Water vapour condenses and forms clouds
• Water then returns to the Earth in form of precipitation from clouds, allowing it to be absorbed by plants, soil or run off into rivers and lakes

Question 3

Steps of the carbon cycle

Answer 3

• Carbon is taken out of the atmosphere by plants and algae during photosynthesis
• Carbon is passed on to animals when they feed on the plants and algae
• It is returned to the atmosphere when the plants, algae and animals respire
• Dead plants and animals are broken down by decomposers, which respire to release carbon dioxide
• If the plants and animals die in conditions where decomposers aren’t present, carbon is converted into fossil fuels
• When fossil fuels are burned, carbon is released back into the atmosphere