1. What role do bacteria play during the nitrogen cycle?
a. Bacteria store nitrogen in wastes.
b. Bacteria convert nitrogen into water.
c. Bacteria turn nitrogen into phosphates.
d. Bacteria transform nitrogen into molecules.

Use the map to answer questions 2-3 :>

2. What continent has the lowest percentage of carbon dioxide output?
a. Asia
b. Australia
c. Europe
d. North America

3. What regions are responsible for the highest percentage of carbon dioxide output?
a. developed regions in the western hemisphere
b. developed regions in the eastern hemisphere
c. developing regions in the western hemisphere
d. developing regions in the eastern hemisphere

4. Which of the following shows an effect on the carbon cycle of the increased burning of fossil fuels??
a. More carbonates remain in fossil fuels.
b. More carbon dioxide is absorbed by organisms.
c. More carbon dioxide is absorbed by the atmosphere.
d. More carbohydrates remain buried deep in the ground.

5. Which of the following are most likely to be the pioneer organisms on a area of bare rock?
a. trees
b. shrubs
c. lichens
d. perennial grasses​