Correct Answer: C

Rationale: The correct answer is C: 'Low-phenylalanine diet.' Children with phenylketonuria (PKU) need to follow a low-phenylalanine diet to manage the condition. Phenylalanine is an amino acid found in protein-containing foods, and individuals with PKU have difficulty metabolizing it, leading to neurological damage and other complications. Therefore, restricting phenylalanine intake is crucial. Choice A, 'High-protein diet,' is incorrect because high protein intake would increase phenylalanine levels, worsening the condition. Choice B, 'Low-fat diet,' and Choice D, 'High-fiber diet,' are not the primary focus for PKU patients. The key dietary intervention for PKU is controlling phenylalanine intake, which is best achieved through a low-phenylalanine diet.

Correct Answer: A

Rationale: The correct answer is A. Vitamins are organic compounds, containing carbon, which is a key characteristic that differentiates them from minerals. Choice B is incorrect because vitamins do not provide energy; they are not a source of calories. Choice C is incorrect as both vitamins and minerals are considered micronutrients due to being essential in small amounts. Choice D is incorrect because while it is true that vitamins are needed in small amounts, this is not the characteristic that sets them apart from minerals.

Correct Answer: C

Rationale: A normal half-cup vegetable portion usually weighs around 100 grams. This weight is a standard measurement for a half-cup serving of vegetables, making choice C the correct answer. Choices A, B, and D are incorrect as they do not align with the typical weight of a half-cup vegetable portion.

Correct Answer: B

Rationale: Children with a history of severe allergic reactions should receive inactivated vaccines because they do not contain live pathogens. Live attenuated vaccines (choice A) contain weakened live pathogens and can potentially trigger an allergic reaction in sensitive individuals. Subunit vaccines (choice C) and recombinant vaccines (choice D) may contain components that could still trigger an allergic response in individuals with a history of severe allergies. Inactivated vaccines are the safest choice for individuals with a history of severe allergic reactions as they do not pose a risk of causing an allergic reaction due to the absence of live pathogens.

Correct Answer: C

Rationale: Peer review is crucial in scientific research to verify the accuracy and validity of research findings. By subjecting research papers to evaluation by experts in the field, peer review ensures that the study's methods, results, and conclusions are robust and reliable. This process helps to maintain high standards of quality in scientific publications, providing credibility to the research. Choices A and D are incorrect because the primary purpose of peer review is not to expedite publication or solely enhance credibility; its core function is to validate the research's accuracy and validity. Choice B, while beneficial, is not the primary reason for peer review; replication is a byproduct of the rigorous evaluation of research methods and findings.