B17 - Organising An Ecosystem

Question 1

Things that affect rate of decay

Answer 1

temperature, oxygen availability, water availability

Question 2

Biogas

Answer 2

contains methane - can be used as fuel
Can be produced by the microorganisms that use decomposing waste material in anaerobic conditions (without oxygen) in a biogas generator

Question 2

What is compost made of

Answer 2

decomposed material

Question 3

Carbon cycle

Answer 3

Carbon dioxide is taken out of the atmosphere during photosynthesis. It is used in photosynthesis- these products make biomass

This carbon is passed on to animals (and microorganisms) when they feed on plants and algae

It is returned to the atmosphere in during respiration by plants, animals and microorganisms during decomposition

If animals and plants die in conditions where decomposing microorganisms are not present, the carbon in their bodies can be converted, over millions of years and significant pressure, into fossil fuels

When wood or fossil fuels are burned in combustion, the carbon within them combines with oxygen and carbon dioxide is released into the atmosphere

Question 4

Water cycle

Answer 4

Water evaporates from oceans, rivers and lakes
Transpiration from plants releases water vapour into the air

The warmer air of the lower atmosphere rises, taking the water vapour with it
The moist air cools down as it rises

Water vapour condenses back into liquid water, forming clouds
Water returns to Earth in the form of precipitation

As the water droplets in the cloud get bigger and heavier, they begin to fall as rain, snow and sleet