During the carbon cycle, animals and plants add carbon dioxide to the atmosphere through cellular respiration, and plants remove carbon dioxide through photosynthesis. The burning of fossil fuels releases more carbon dioxide into the atmosphere, contributing to global warming.
<span>Fats, oils and cholesterol are all types of lipids.Lipids are biomolecules that consist in long chains of carbons and hydrogen, insolubles in water (becauise they are not polar). Many lipids have in common the functional group corboxilic, COOH. Cholesterol, fats and oils all have carboxlic group. </span>
I think the answer to this is 2.