Final answer:
The carbon cycle involves the movement of carbon between the atmosphere, living organisms, and the Earth's surface, starting with atmospheric carbon dioxide. The nitrogen cycle involves the movement of nitrogen between the atmosphere, living organisms, and the Earth's soil, starting with atmospheric nitrogen gas.
Step-by-step explanation:
The carbon cycle is the process by which carbon moves between the atmosphere, living organisms, and the Earth's surface. It starts with atmospheric carbon dioxide, which is taken in by plants through a process called photosynthesis. The carbon is then passed along the food chain as organisms consume plants or other organisms, and released back into the atmosphere through respiration or decomposition.
The nitrogen cycle is the process by which nitrogen moves between the atmosphere, living organisms, and the Earth's soil. It starts with atmospheric nitrogen gas, which is converted into usable forms by nitrogen-fixing bacteria in the soil. Plants obtain nitrogen from the soil and incorporate it into their tissues. When plants and animals die, decomposers break down their organic matter, releasing nitrogen back into the soil and, eventually, back into the atmosphere as nitrogen gas.