The backbone is made of many small units of bone or cartilage. what is each unit called?

Text version using the diagram above, match the description to the corresponding location in the carbon cycle model. provide the letter only. carbon dioxide is converted to sugar used for food. carbon trapped in fossil fuels is converted to carbon dioxide. organic carbon is converted to fossil fuels. carbon dioxide is converted to carbonates. sugar is broken down and converted to carbon dioxide. location location location location location