Correct Answer: A

Rationale: Oligosaccharides are carbohydrates composed of 3 to 10 monosaccharide units, making choice A the correct answer. Choice B is incorrect as oligosaccharides do not contain partially digested starch. Choice C is incorrect as nonnutritive sweeteners are a different category of compounds. Choice D is incorrect as oligosaccharides are not primarily used for weight management.

Correct Answer: A

Rationale: The correct answer is the radical group (R-group) because it is the unique side chain that differentiates each amino acid. The amino group (choice B) and carboxyl group (choice C) are functional groups common to all amino acids but do not make them unique. The peptide bond (choice D) is the bond formed between amino acids in a protein chain, not the group that makes each amino acid unique.

Correct Answer: B

Rationale: The correct answer is B, a peanut butter sandwich. A peanut butter sandwich combines grains from the bread and proteins from the nuts in the peanut butter, providing complementary proteins. This combination offers all essential amino acids. Choices A, C, and D do not contain complementary proteins as they lack the combination of different protein sources necessary to provide a complete amino acid profile.

Correct Answer: D

Rationale: The correct answer is D, peptide bond. A peptide bond is formed through a dehydration synthesis reaction between the amine group of one amino acid and the carboxyl group of another amino acid. This bond is crucial in protein synthesis. Choices A, B, and C are incorrect. A double bond involves sharing two pairs of electrons, a hydrogen bond is a weak attraction between a hydrogen atom and an electronegative atom, and a carboxyl bond is not a common term in biochemistry.

Correct Answer: A

Rationale: Branched chain amino acids, such as leucine, isoleucine, and valine, are essential in preventing muscle breakdown. Therefore, they may be particularly important for a patient with cancer-related malnutrition, where maintaining muscle mass is crucial. Marasmus is a severe form of malnutrition characterized by energy deficiency, not specifically related to cancer. Cardiovascular disease and severe depression do not have a direct correlation with the need for branched chain amino acids to prevent muscle breakdown.