What is the smallest amount of a nutrient that, when consumed over a prolonged period, maintains a specific function?

Correct Answer: B

Rationale: The correct answer is 'B: nutrient requirement.' The nutrient requirement refers to the smallest amount of a nutrient that, when consumed over a prolonged period, maintains a specific function in the body. This amount ensures the body's optimal functioning and health. Choice A, 'nutrient allowance,' is incorrect as it does not specifically refer to the minimum amount needed for bodily functions but rather suggests a broader term. Choice C, 'nutrient tolerable limit,' is incorrect as it pertains to the maximum amount of a nutrient that can be consumed without adverse effects. Choice D, 'nutrient adequate intake,' is incorrect as it refers to the recommended average daily intake level of a nutrient to meet the requirements of most healthy individuals.

Correct Answer: B

Rationale: The correct answer is B: Water helps transport nutrients and waste products. Water plays a crucial role in the body by aiding in the transportation of essential nutrients to cells and removing waste products. While water is essential for various metabolic processes, it does not provide calories for energy (choice A). Although water can act as a solvent for biological reactions (choice C), its primary function is not as a solvent. Additionally, while water does help in regulating body temperature to some extent, its main role is not to maintain body temperature (choice D).

Correct Answer: B

Rationale: Nutrigenomics is the study of how diet affects gene expression, influencing health outcomes and disease risk. Epigenetics (choice A) involves changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Genomics (choice C) is the study of an organism's entire genome. Genetics (choice D) is the study of heredity and the variation of inherited characteristics.

Correct Answer: A

Rationale: Correct. Age is one of the primary factors influencing nutrient needs. Different life stages, such as infancy, childhood, adulthood, and old age, require varying amounts of nutrients. Gender (choice B) can influence nutrient needs to some extent, but age plays a more significant role. Genetics (choice C) may affect how individuals metabolize certain nutrients but is not a primary factor in determining overall nutrient needs. Physical activity level (choice D) can impact energy requirements but is not as fundamental as age in influencing overall nutrient needs.

Correct Answer: A

Rationale: The main function of proteins in the body is to provide structural components like muscles, skin, and bones. Proteins are essential for growth, repair, and maintenance of body tissues. While proteins play a role in various physiological functions, their primary function is not to assist in the absorption of vitamins (Choice B), help with the transport of nutrients in the blood (Choice C), or maintain fluid balance (Choice D).