Oily, waxy, fats found in living things are called

• A. Amino acids
• B. Sweat
• C. Trans fats
• D. Lipids

Answer: (D)

The main idea here is that a broad group of oily, waxy substances found in living organisms are lipids. Lipids are a diverse set of biomolecules that don’t dissolve in water, and they include fats, oils, waxes, as well as phospholipids in cell membranes and steroid molecules. Their functions span long-term energy storage, insulation and protection, forming and signaling within cell membranes, and various regulatory roles. So when you hear “oily, waxy fats,” that points to lipids as the general category that covers fats, oils, and waxes in living things. Amino acids are the building blocks of proteins, not fats; sweat is a bodily secretion; trans fats are a specific type of lipid, but the question asks for the broader category rather than a particular subtype.