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: A

Rationale: Patients with periodontal disease may require increased protein intake due to the physiological response to inflammation and infection, which can negatively impact protein synthesis. Protein is essential for wound healing and tissue repair, and an infection can increase the body's protein requirements. Therefore, ensuring an adequate protein intake is particularly important for these patients. Choice A is correct because the statement and reason are both accurate and directly related to each other, supporting the increased protein needs in patients with periodontal disease. Choices B, C, and D are incorrect as they do not accurately assess the relationship between the statement and the reason provided in the question.

Correct Answer: B

Rationale: Iron is an essential nutrient for the body, and while it can be found in many different types of foods, the amounts can vary significantly. Cheese, while a good source of other nutrients like calcium and protein, is not a particularly rich source of iron. On the other hand, clams, legumes, and dried fruits are known to contain higher levels of iron. Therefore, among the provided choices, cheese is considered a poor source of iron. It's important to note that a balanced diet should include a variety of foods to ensure the intake of all necessary nutrients.

Correct Answer: D

Rationale: Fructose is a sugar naturally found in honey and fruit. While bread contains carbohydrates, it does not primarily consist of fructose. Gelatin desserts are more likely to contain added sugars like sucrose rather than fructose. Sugar-coated cereals typically contain sucrose or other added sugars, not just fructose. Therefore, the correct answer is honey and fruit as they naturally contain fructose.

Correct Answer: C

Rationale: Fat provides 9 kcal per gram, so 35 grams of fat provides 315 kcal. Therefore, the correct answer is C. Choice A (140) is incorrect because it doesn't consider the energy content of fat. Choice B (245) is incorrect as it miscalculates the kilocalories provided by 35g of fat. Choice D (360) is incorrect because it overestimates the kilocalories provided by 35g of fat.