1. Photosynthesis in the Earth's forests produces about half of the oxygen in the atmosphere. Photosynthesis in the Earth's oceans produces the other half of the oxygen in
the atmosphere. Why do you think so much photosynthesis occurs in the oceans? Think
about what type of organisms perform photosynthesis. (8 points)
2. The rain forests of South America are very active photosynthetic zones. Although plants
around the world use photosynthesis, these areas are more productive than other parts of
the planet.
a) About half of the forests that covered the Earth in the early 1900s have been cut down.
Discuss the impact this has on carbon dioxide levels in the atmosphere. Support your
answer.