The Carbon Cycle
1.
In the table below are statements about carbon stores. Decide if they are true or false.
Statement about Carbon stores
T
Short term stores of carbon are found in plants on land and in oceans
Long term stores of carbon are found in land-based and marine animals
Carbon is found in the atmosphere as ammonia
More short term stores of carbon are found in intermediate and deep ocean waters as
dissolved carbon dioxide
In cold water carbon will sink to the ocean floor and remain for 500 years
On land, long –term stores of carbon are found in coal, oil and gas deposits
Coal, oil and natural gas are fossil fuels that are formed from dead plants and
animals
A small amount of long-term carbon stores are found in marine sediments and
sedimentary rock.
F
2. Look at the carbon cycle in your data booklet to answer these questions.
Questions
How many gigatonnes of carbon is stored as dissolved organic carbon?
How many gigatonnes of carbon is stored as soil and organic matter?
How many gigatonnes of carbon found as CO2 in the atmosphere?
How many gigatonnes of carbon is stored in marine life?
How many gigatonnes of carbon is removed from the atmosphere by
photosynthesis?
How many gigatonnes of carbon is added to the atmosphere by human
activities?
How many gigatonnes of carbon is stored in terrestrial vegetation?
What is the net carbon input by sea surface gas exchange?
Answers
The Nitrogen Cycle
1. How is nitrogen used in the bodies of living organisms? In protein in their muscles and in DNA.
2. Use the circle to make a circle graph of the percent of air that is nitrogen.
B. Use the diagram in your data booklet to answer the following questions.
1. Where is most of the nitrogen (N2) on earth found?
2. What is the process that takes nitrogen gas (N2) and converts it into NH4+?
3. Name the process that converts NH4+ into NO2-?
4. What is the form of nitrogen that is taken up by plants?
5. What kinds of bacteria convert nitrogen gas (N2) into NH4+?
6. How does nitrogen get into animals?
7. How does NH4+ and NO2- become dissolved in lakes and rivers?
________________
_atmosphere___
_nitrogen-______
_fixation________
__Nitrification___
__NO3-__________
Nitrogen fixing bacteria
_Animals eat plants
Leaching and run off
Acid precipitation___
How is nitrogen gas converted directly to NO3-?
9. What kinds of bacteria convert NH4+ into NO2-?
10. Name the process that returns NO3- to N2 in the atmosphere.
11. How do humans add to the amount of NH4+ and NO3- in the soil?
12. What kinds of bacteria convert NO3- to N2 in the atmosphere?
13. Which processes add NH3, NO2, NO into the atmosphere?
8.
Atmospheric fixation (lightning)
Nitrifying bacteria
Denitrification___
fertilizer application
Denitrifying bacteria
Nitrogen oxides _
_from industry___
_decomposers__
(bacteria and fungi)
14. What kinds of organisms return NH4+ into the soil after an animal dies?
Phosphorus Cycle
1.
3.
How is phosphorus stored? In phosphorus rock and sediment
What is weathering and what does it do to phosphorus? Weathering is the breaking down of rock. It releases
phosphate into the soil.
4.
Look at the Phosphorus Cycle in your Data Booklet and answer the questions in the table below.
Questions
How many megatonnes of phosphorus are stored in terrestrial
organisms?
How many megatonnes of phosphorus are found as mineable
phosphate rock?
How do humans contribute to the phosphate cycle?
How many megatonnes of phosphorus are stored as shallow ocean
sediments?
What kind of bacteria contribute to phosphate in the soil?
Answers
What is the form of phosphate found in water?