A chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid is the:

Correct Answer: C

Rationale: The correct answer is C. Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds. Therefore, the number of double bonds is the chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid. Choices A, B, and D are incorrect because the distinguishing factor between saturated and unsaturated fatty acids lies in the presence or absence of double bonds, not in the arrangement of carbon atoms, number of oxygen molecules, or food source.

Correct Answer: C

Rationale: The primary function of protein in the diet is to build and repair tissues. Proteins are essential for the growth, maintenance, and repair of body tissues like muscles, skin, and organs. While proteins can be a source of energy, their primary role is not to supply energy, making choice A incorrect. Choice B is also incorrect as proteins do not synthesize vitamins; rather, they are essential nutrients themselves. Choice D is inaccurate because glycogen is a form of stored glucose in the body, not a function of protein.

Correct Answer: B

Rationale: Lignin is the correct answer because it is a type of fiber that is not a carbohydrate and provides structure to plant cell walls. Gums (choice A), pectin (choice C), and cellulose (choice D) are all types of dietary fiber that are carbohydrates. Gums are a type of soluble fiber, pectin is found in fruits and is a soluble fiber, and cellulose is a type of insoluble fiber found in plant cell walls.

Correct Answer: B

Rationale: The correct answer is B: Supply energy. The primary function of macronutrients such as carbohydrates, fats, and proteins is to supply energy for various bodily functions. Choices A, C, and D are incorrect because while regulating metabolic processes, maintaining homeostasis, and controlling cellular activity are essential functions in the body, they are not the primary roles of macronutrients. Macronutrients mainly serve as a source of energy to support daily activities and bodily functions.

Correct Answer: B

Rationale: The correct answer is B: the American Diabetes Association. The American Dietetic Association collaborated with the American Diabetes Association to devise the Exchange Lists for Meal Planning. This collaboration aimed to assist individuals, especially those with diabetes, in planning balanced meals. Choices A, C, and D are incorrect as they were not involved in the development of the Exchange Lists.