What should be recommended to help prevent early childhood caries (ECC) in infants?

Correct Answer: A

Rationale: The correct answer is 'A: Avoid giving the infant nighttime bottles' because prolonged exposure to sugars in milk during the night can lead to caries. Options 'B: Have the infant drink pasteurized skim milk' and 'D: Give the infant fruit juice to drink' are not recommended as they contain sugars that can cause cavities, especially in infants. Option 'C: Feed the infant iron-rich foods' is incorrect because while a balanced diet is important, iron-rich foods do not directly prevent caries development.

Correct Answer: C

Rationale: The correct answer is 'health care agent.' A health care agent is appointed through a durable power of attorney to make medical decisions on behalf of a patient who becomes incapacitated. The term 'witness' (choice A) is incorrect because a witness only observes the signing of the directive and does not make decisions. 'Primary caregiver' (choice B) is also incorrect as they may provide care but are not necessarily legally empowered to make decisions. 'State proxy' (choice D) is not commonly used in the context of advance directives or health care decision making, making it an incorrect choice.

Correct Answer: D

Rationale: Lipids are carried in the bloodstream in the form of lipoproteins. Lipoproteins are complexes of proteins and lipids that transport fats to various parts of the body. While micelles, glycolipids, and lecithin are all related to lipid metabolism, they are not the primary carriers of lipids in the bloodstream. Micelles are small lipid clusters in the intestines, glycolipids are lipids with a carbohydrate attached, and lecithin is a type of phospholipid. Therefore, lipoproteins are the correct answer as they are specifically designed for transporting lipids through the bloodstream.

Correct Answer: B

Rationale: The correct answer is B. The classification of the 20 common amino acids is not based on the properties of their side chains, but rather on the structure of their amino and carboxyl groups. These groups are consistent among all amino acids, while the side chains, also known as R groups, are what vary and give each amino acid its unique properties. Choice A is correct because proteins are indeed composed of amino acids. Choice C is incorrect because while the side chains of amino acids can vary, the general structure of an amino acid - a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain - is consistent. Choice D is correct because amino acids do polymerize to form long chains called polypeptides, which can then fold into complex shapes to form proteins.

Correct Answer: A

Rationale: The correct answer is 'A: Avoid giving the infant nighttime bottles' because prolonged exposure to sugars in milk during the night can lead to caries. Options 'B: Have the infant drink pasteurized skim milk' and 'D: Give the infant fruit juice to drink' are not recommended as they contain sugars that can cause cavities, especially in infants. Option 'C: Feed the infant iron-rich foods' is incorrect because while a balanced diet is important, iron-rich foods do not directly prevent caries development.

Correct Answer: C

Rationale: The healthiest approach for an overweight pregnant woman is to delay weight loss until after pregnancy. During pregnancy, the body needs sufficient nutrition and energy to support the growth and development of the baby. Attempting to lose weight during pregnancy, especially significant amounts, may compromise the health of both the mother and the baby. Increasing protein intake to 35% of total calories or energy intake by 550 calories per day without professional guidance may lead to an unbalanced diet, which is not optimal for pregnancy. The focus should be on maintaining a balanced, nutrient-rich diet and appropriate weight gain during pregnancy.

Correct Answer: C

Rationale: Infection is a common manifestation of nephrotic syndrome. This is due to the loss of immunoglobulins in the urine, which weakens the body's immune defenses. Dehydration (Choice A) and uremia (Choice B) can be symptoms of kidney dysfunction but are not specific manifestations of nephrotic syndrome. Low blood lipids (Choice D) is incorrect as nephrotic syndrome typically results in high, not low, blood lipid levels due to the body's attempt to replace lost proteins.

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: D

Rationale: The correct answer is D. Polyunsaturated fatty acids. Polyunsaturated fatty acids have two or more double bonds in their carbon chains, making them less stable and more prone to oxidation. This characteristic distinguishes them from saturated fatty acids (Choice A), which have single bonds between carbon atoms providing stability. Monounsaturated fatty acids (Choice B) contain only one double bond, and trans fatty acids (Choice C) can have varying numbers of double bonds but are not specifically defined by having two or more double bonds.