Nokea
Which physiologic role does vitamin C play in the body?
- A. Transcribing DNA to RNA
- B. Absorption and regulation of calcium
- C. Protects integrity of cellular membranes
- D. Catalyst for synthesis of blood-clotting factors
Correct Answer: C
Rationale: Vitamin C plays a crucial role in protecting the integrity of cellular membranes. It is essential for collagen synthesis, which is important for wound healing and maintaining skin, blood vessels, and other tissues. Choice A is incorrect as the transcription of DNA to RNA is facilitated by vitamin A. Choice B is incorrect as calcium absorption and regulation are functions of vitamin D. Choice D is incorrect as vitamin K serves as a catalyst for the synthesis of blood-clotting factors, not vitamin C.
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Each statement is true of fat-soluble vitamins, except one. Which is the exception?
- A. Fairly stable to heat, such as during cooking
- B. Contain carbon
- C. Stored in the pancreas
- D. Absorbed in the intestine along with fats and lipids in food
Correct Answer: C
Rationale: Fat-soluble vitamins are not stored in the pancreas; they are stored in the liver and fatty tissues. Choice A is correct as fat-soluble vitamins are fairly stable to heat. Choice B is also correct as fat-soluble vitamins contain carbon. Choice D is correct as fat-soluble vitamins are absorbed in the intestine along with fats and lipids in food.
When carbohydrates are eliminated from the diet to lose weight, which nutrients are most likely to become insufficient?
- A. Iron, fiber, and protein
- B. Iron, fiber, and vitamin K
- C. Vitamin A and vitamin C
- D. Iron, fiber, and B vitamins
Correct Answer: D
Rationale: Iron, fiber, and B vitamins are most likely to become insufficient when carbohydrates are eliminated from the diet to lose weight. Carbohydrates are a primary source of B vitamins and fiber in the diet. Iron can also be obtained from plant-based sources like legumes and whole grains, which are often eliminated when carbohydrates are restricted. Choices A, B, and C are incorrect because protein, vitamin K, vitamin A, and vitamin C are not primarily sourced from carbohydrates and are less likely to become insufficient solely due to carbohydrate elimination.
Which set of guidelines is intended to assess nutrient adequacy or plan intakes of population groups, not individuals?
- A. Old Recommended Dietary Allowances (RDA)
- B. Estimated Average Requirement (EAR)
- C. New Recommended Dietary Allowances (RDA)
- D. Tolerable Upper Intake Level (UL)
Correct Answer: B
Rationale: The Estimated Average Requirement (EAR) is specifically designed to assess nutrient adequacy or plan intakes for population groups, not for individuals. The Old and New Recommended Dietary Allowances (RDA) are meant for individuals, not groups, as they provide guidelines for specific nutrient intake levels for healthy individuals. The Tolerable Upper Intake Level (UL) is used to set the highest level of nutrient intake that is likely to pose no risk of adverse health effects for most individuals in a group, which is different from assessing nutrient adequacy for groups.
Each of the following describes the physiologic roles of water, except one. Which is the exception?
- A. Acts as a solvent for chemical reactions.
- B. Maintains stability of body fluids.
- C. Enables transport of nutrients and excretion of waste.
- D. Regulates temperature by pooling as perspiration on skin.
Correct Answer: D
Rationale: The correct answer is D. Water regulates body temperature by evaporating as perspiration from the skin, not by pooling. When sweat evaporates from the skin, it takes away heat, which helps cool the body. Choices A, B, and C are correct because water acts as a solvent for chemical reactions, maintains the stability of body fluids, and enables the transport of nutrients and excretion of waste, respectively.
When rickets occurs, how is the alveolar bone affected compared to other bones in the body?
- A. Both statements are true.
- B. Both statements are false.
- C. The first statement is true; the second is false.
- D. The first statement is false; the second is true.
Correct Answer: A
Rationale: Both statements are true. When rickets occurs, the alveolar bone is affected similar to other bones in the body, with the trabeculae of the alveolar bone also weakening. In addition to damaged alveolar bone caused by vitamin D deficiency, dental changes include delayed dentition and small molars. The other choices are incorrect because both statements provided are accurate based on the effects of rickets on the alveolar bone.