Cycling WebQuest
Directions: Visit the following websites and answer the related questions. Your goal is to gain a better understanding of the carbon and nitrogen cycles.
Background: In biogeochemical cycles (including carbon, water and nitrogen cycles), elements are transported between the atmosphere, biosphere (living things), hydrosphere (water), and geosphere (rocks, minerals, and soils). These cycles help us remember that Earth is a complex system. Carbon Cycle:
Go to http://www.windows.ucar.edu/tour/link=/earth/Water/co2_cycle.html and answer these questions:
Directions: Visit the following websites and answer the related questions. Your goal is to gain a better understanding of the carbon and nitrogen cycles.
Background: In biogeochemical cycles (including carbon, water and nitrogen cycles), elements are transported between the atmosphere, biosphere (living things), hydrosphere (water), and geosphere (rocks, minerals, and soils). These cycles help us remember that Earth is a complex system. Carbon Cycle:
Go to http://www.windows.ucar.edu/tour/link=/earth/Water/co2_cycle.html and answer these questions:
- Draw the carbon cycle (on a separate piece of paper)
- How does carbon exist in the atmosphere?
- How are fossil fuels created? Explain.
- Describe two ways that carbon enters the atmosphere.
- How are the oceans involved in the carbon cycle?
- How is the temperature of the Earth partly controlled by carbon?
- What role do rocks have within the carbon cycle?
Go to http://www.windows.ucar.edu/earth/climate/carbon_cycle.html to play the carbon cycle
game. You are a carbon atom!
- Where are you starting within the carbon cycle?
“Click to begin your journey”
- How much of the atmosphere is made of carbon dioxide (CO2)?
- By how much has CO2 increased in the atmosphere during the past 150 years?
As you work through this game, take some notes about where you go as a carbon atom. Make sure
you visit all reservoirs!
11. Next stop = Land Plants
What did you learn?
Carbon is taken out of the atmosphere by plants and with the help of the sun to create into nutrients. As more carbon is taken out of the atmosphere plants will be able to grow faster. Plants release carbon into the atmosphere with a process called respiration.
12. Next stop = Soil
What did you learn?
Decomposing plants and animals are called detritus. Soil is made up of inorganic parts like soil, silt, and clay. About 3% of carbon is held in soil. As bacteria and fungi break down detritus, carbon is sent to the atmosphere.
The deep ocean accounts for more than 65% of the Earth’s carbon.
How much carbon does the surface ocean absorb from the atmosphere each year?
90 Gigatons
True or False: When plants die and decay, they bring carbon into soil.
True
- Next stop = Surface Ocean
The ocean absorbs more carbon from the atmosphere then land does. Cold water absorbs it better than warm. The ocean approximately takes in 90 Gigatons per year.
14. Next stop = Marine Life
What did you learn?
Carbon is essential to marine life because phytoplankton take in carbon to create the nutrients needed, but too much of it is harmful to marine organisms such as algae, mollusks, and coral.
15. Next stop = Deep Ocean
What did you learn?
It gets carbon from circulation with the surface ocean along with decaying marine life. Carbon can stay in the deep ocean trenches for hundreds of years before finally moving on.
When carbon enters the deep ocean, how long does it stay there?
It can stay for hundreds of years before moving on.
True or False: Phytoplankton are tiny plants and algae that float in the ocean and take up carbon
dioxide as they grow.
True
True or False: Plants both absorb CO2 from the atmosphere and release it into the atmosphere.
Nitrogen Cycle:
True
Go to http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html and
answer these questions.
16. What are the two conditions under which nitrogen will react with oxygen? (In other
words, what is necessary for nitrogen in the air to combine with oxygen?)
In high temperatures and pressures found near high electricity source.
- What are the two compounds that are formed when nitrogen combines with oxygen?
- How does nitric acid (HNO3) form?
- Why is nitric acid (HNO3) important?
Go to: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/NitrogenCycle.html and
answer these questions.
- What percentage of the air we breathe is nitrogen?
21. Even though considerable nitrogen is available in the air, most plants do not use the nitrogen
(N2) found in the air. Why not?
Because they can not use this form plants must secure their nitrogen.
- In what compounds can plants use nitrogen?
- How do animals get the nitrogen they need?
24. Atmospheric nitrogen (N2) is pretty inert. This means that it does not easily break apart.
When molecules do not break apart easily, it is difficult (or impossible) for organisms to use
them as a nutrient source. As a result, nitrogen fixation is the term used to describe the
process of breaking up N2.
a. What is atmospheric fixation?
Lighting that breaks nitrogen molecules and makes their atoms combine with oxygen to form nitrogen oxides. They dissolve in rain, forming nitrates.
b. What is industrial fixation? [This is how artificial fertilizers are made.]
The combination of catalyst, atmospheric nitrogen and hydrogen for ammonia which can be used as fertilizer directly.
c. What is biological fixation? (In your answer, describe the types of plants associated
with the symbiotic relationship.)
The ability to fix nitrogen is found in certain bacteria and archaea. They establish symbolic relationships with legume family like soybeans, alfalfa.
Go to: http://www.physicalgeography.net/fundamentals/9s.html and answer these questions.
25. Draw the nitrogen cycle: On a separate piece of paper: (Remember there are other
diagrams on the previous websites.) If you’re not sure what a term means, look through the
reading and links for help.
- Why is nitrogen needed by plants and animals?
Go to http://www.mbgnet.net/fresh/cycle/index.htm. Answer the following questions.
- Define "water cycle".
- What fraction of the Earth’s surface is covered in water?
3. What percentage of all the Earth’s water is in a form that is useable to humans and land
animals?
About 1%
Click on http://www.mbgnet.net/fresh/cycle/concepts.htm. Answer the following questions.
1. Evaporation is the process where a liquid changes from its liquid state to a
gaseous state.
- Why is evaporated water so clean?
3. Condensation occurs when a gas is changed into a liquid.
4. Condensation is the opposite of evaporation.
5. When the temperature and atmospheric pressure are right, the small droplets of
water in clouds form larger droplets and precipitation occurs.
- Define transpiration:
- Define percolation:
Go to http://www.mbgnet.net/fresh/cycle/cycle.htm. Answer the following questions.
1. Using the terms "evaporation", "condensation", and "precipitation", explain the water
cycle in your own words.
The water cycle begins with evaporation where the heat from the sun turns the water into steam or vapor and it rises to the atmosphere. Next is condensation, where water turns into rain clouds waiting to begin to pour. And finally come precipitation where the rain falls and stays on Earth's surface or into bodies of water.
- What factor is most important in determining whether water is a solid, liquid, or gas?
- Is the amount of water on Earth always changing or is it a constant amount?