1. The Earth's carbon cycle consists of the flow, cycling, and recycling of all of the carbon on the Earth. Every living organism's composition includes the element carbon. How does carbon become part of living organisms?

Carbon is in the air from pollution and burning fossil fuels ... etc. Plants use it to convert it into sugars and oxygen. Animals eat plants and obtain carbon. They return it to the atmosphere through cellukar repiration that produces carbon dioxide and water.

Plants get carbon from photosynthesis by pulling carbon from the air. Animals get carbon through eating plants.