Where is most of Earth's carbon stored

answer:

Most of Earth's carbon—about 65,500 billion metric tons—is stored in rocks. The rest is in the ocean, atmosphere, plants, soil, and fossil fuels. Carbon flows between each reservoir in an exchange called the carbon cycle, which has slow and fast components.

Explanation:

"do a testcross with a homozygous recessive plant."

geologic time scale (for gradpoint) =)