Correct Answer: A

Rationale: The correct answer is A. The U.S. Department of Agriculture collaborates with the Department of Health and Human Services to publish and revise the Dietary Guidelines for Americans. This collaboration ensures that the guidelines encompass both agricultural and health aspects. Choices B, C, and D are incorrect as they are not directly involved in the publication and revision of the Dietary Guidelines. The National Institutes of Health focuses on medical research, the National Academy of Sciences provides independent scientific advice, and the Food and Nutrition Board is a part of the National Academies of Sciences, Engineering, and Medicine.

Correct Answer: B

Rationale: A normal weight-to-height ratio is a reliable indicator of good nutritional status as it suggests that the person is well-nourished and not underweight or overweight. Small muscle mass (choice A) can indicate malnutrition, a smooth tongue (choice C) can be a sign of vitamin deficiencies, and fragile skin (choice D) can be a sign of poor nutrition or other health issues, but they are not as direct indicators of good nutritional status as a normal weight-to-height ratio.

Correct Answer: B

Rationale: Peristalsis is the correct answer because it refers to the rhythmic contractions that propel food through the intestinal tract by pushing it along the digestive system. Segmentation, on the other hand, refers to the mixing movements in the intestines rather than the forward movement of food. Cardiospasm is a condition characterized by difficulty swallowing due to the inability of the esophagus to relax, and pendular movements are a type of motility found in the small intestine but do not specifically refer to the propulsion of food.

Correct Answer: B

Rationale: Biochemistry is the correct answer because it focuses on understanding the chemical processes related to nutrition and how nutrients affect the body. Anatomy (choice A) primarily deals with the structure of organisms, not the chemical processes of nutrition. Physics (choice C) deals with energy and matter, not specifically related to nutrition. Pharmacology (choice D) focuses on drugs and their interactions with the body, not directly related to nutrition and its effects on health.

Correct Answer: C

Rationale: Dietary guidelines are designed to assist individuals in making smart food choices by providing recommendations on what to eat to maintain good health. While portion sizes may be a part of these guidelines, they are not the primary focus. Designing a personal food plan involves individual preferences and needs, which may go beyond general guidelines. Avoiding excessive nutrient intakes is important, but dietary guidelines aim to provide balanced recommendations rather than just focusing on avoiding excess.