B7: RECYCLING MATERIALS

Question 1

How are elements and mineral ions recycled?

Answer 1

-elements (C, H2 and O2)/ mineral ions (NO3, Mg and P) are taken in by plants and used to make compounds (eg: carbohydrates, proteins and fats)
-these elements are passed up the food chain when animals consume plants and then passed on to other animals
-elements are returned to the environment in waste products/when animals die and decay
-materials decay as they are digested by microorganisms
-this returns mineral ions back to the soil for use by plants

Question 2

What are some examples of plant waste products?

Answer 2

-CO2
-H2O
-O2

Question 3

What are some examples of animal waste products?

Answer 3

-faeces
-urine

Question 4

optimum conditions for decomposition?

Answer 4

-O2 rich (aerobic)
-warm
-moist

Question 5

What are the stages involved in the water cycle?

Answer 5

-evaporation and transpiration
-condensation
-precipitation
-surface run-off