Illustration shows carbon cycle.

Figure 3–17 The Carbon Cycle Carbon is found in several large reservoirs in the biosphere. In the atmosphere, it is found as carbon dioxide gas (CO2); in the oceans, as dissolved carbon dioxide; on land, in organisms, rocks, and soil; and underground, as coal, petroleum, and calcium carbonate. Interpret Visuals What is one of the processes that takes carbon dioxide out of the atmosphere?

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Scientists know a great deal about the biological, geological, chemical, and human processes that are involved in the carbon cycle, but important questions remain. How much carbon moves through each pathway? How do ecosystems respond to changes in atmospheric carbon dioxide concentration? How much carbon dioxide can the ocean absorb? Later in this unit, you will learn why answers to these questions are so important.

In Your Notebook Describe one biological, one geological, one chemical, and one human activity that is involved in the carbon cycle.


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Table of Contents

Miller & Levine Biology UNIT 1 The Nature of Life UNIT 2 Ecology UNIT 3 Cells UNIT 4 Genetics UNIT 5 Evolution UNIT 6 From Microorganisms to Plants UNIT 7 Animals UNIT 8 The Human Body A Visual Guide to The Diversity of Life Appendices Glossary Index Credits