1. Which of the following lists the main carbon-containing macromolecules?, A. Vitamins, minerals, water, and salt, B. Carbohydrates, lipids, proteins, and nucleic acids, C. Proteins, minerals, oxygen, and water, D. Carbohydrates, vitamins, salts, and enzymes, 2. What are the main structural and functional elements of biological macromolecules?, A. Carbon atoms and chemical groups, B. Water molecules and minerals, C. Oxygen atoms and salts, D. Vitamins and enzymes, 3. Why is carbon called the backbone of life?, A. Because carbon is found only in carbohydrates, B. Because carbon cannot bond with other atoms, C. Because living organisms consist mainly of carbon-based compounds, D. Because carbon dissolves easily in water, 4. Why can carbon form a large variety of molecules?, A. Because carbon can form only one bond, B. Because carbon can bond with four other atoms or groups of atoms, C. Because carbon cannot bond with hydrogen, D. Because carbon is always positively charged, 5. What are hydrocarbons?, A. Organic molecules consisting only of carbon and oxygen, B. Inorganic molecules consisting of hydrogen and oxygen, C. Organic molecules consisting only of carbon and hydrogen, D. Molecules consisting of carbon, nitrogen, and phosphorus, 6. Why do petroleum and fats not dissolve in water?, A. Because they have hydrophilic properties, B. Because they contain ionic bonds, C. Because they have hydrophobic properties, D. Because they are made only of water

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