Explain how a carbon atom in carbon dioxide becomes a hydrocarbon and organic compound before becoming carbon dioxide again.

See below

Explanation:

Used in photosynthesis to become glucose, converted into glycogen in the body. Lipogenesis then converts it into fat, which is then again metabolized in respiration to become CO2

no i don't feel that humans have oversubscribed some medications

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.