B4.1.6 Nuutrient Cycling

Question 1

What materials are cycled

Answer 1

Carbon dioxide
Nitrogen
Water

Question 2

Nitrogen cycling

Answer 2

Nitrogen exists in the soil as nitrates dissolved in water.
The water (containing the dissolved nitrates) is taken up by the roots and the nitrates are used to make proteins.
When the plant is eaten, the nitrogen compounds are passed on to an animal.
When the plants and animals die, these compounds are broken down and released back into the soil as ammonia.
Animals also put nitrogen back into the soil in faces and urea (in urine).

Question 3

Water cycle

Answer 3

Precipitation
Percolation
Transpiration +evaporation
Condensation
Cooling