Which of the following is a poor food source of iron?

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: The correct answer is D. The stomach is protected from gastric acid by a thick mucus lining that acts as a physical barrier, preventing the acid from eroding the stomach walls. Enzymes in the stomach help with digestion but do not play a significant role in protecting the stomach from acid damage, so choice A is incorrect. While some bacteria in the stomach can be beneficial, they do not primarily protect the stomach from gastric acid, making choice B incorrect. Bicarbonate, a base, can neutralize acid, but it is not the primary defense mechanism against gastric acid in the stomach, so choice C is also incorrect.

Correct Answer: A

Rationale: Carbohydrate digestion begins in the mouth. The enzyme amylase, found in saliva, starts the process by breaking down starches into sugars. The esophagus is a passageway for food to reach the stomach and does not participate in digestion. The stomach mainly digests proteins and is not the primary site for carbohydrate breakdown. While the small intestine does play a crucial role in digesting carbohydrates, it is not where the process initiates. Therefore, the correct answer is the mouth.

Correct Answer: B

Rationale: It is false that the major determinant of a person's total cholesterol levels is the amount of cholesterol in their diet. While dietary cholesterol can have some impact on total cholesterol levels, it is not the major determinant. The amount and types of fats consumed, particularly saturated and trans fats, have a more significant impact on blood cholesterol levels. Therefore, a diet high in these types of fats can lead to high cholesterol, irrespective of the amount of dietary cholesterol consumed. This is why it is essential to maintain a balanced diet with a limited intake of saturated and trans fats.

Correct Answer: D

Rationale: The Dietary Reference Intake (DRI) for protein is primarily determined by an individual's body weight. This is because the body's protein requirement is proportionate to its size, which is generally reflected in the body weight. Therefore, choice D is correct. Choices A, B, and C are incorrect: While factors such as fatty acid intake, gender, and height can influence an individual's overall nutritional needs, they do not directly determine the DRI for protein.