Nokea
Each statement is true of calcium within saliva, except one. Which is the exception?
- A. Saliva is supersaturated with calcium.
- B. Saliva is a source of calcium to mineralize an immature or demineralized enamel surface.
- C. Calcium and phosphate in saliva provide a buffering action.
- D. Calcium within saliva increases dental caries.
Correct Answer: D
Rationale: The correct answer is D. Calcium within saliva does not increase dental caries; in fact, the buffering action provided by calcium and phosphate in saliva inhibits caries formation by preventing the dissolution of enamel by plaque biofilm. Choice A is correct as saliva is indeed supersaturated with calcium. Choice B is correct as saliva serves as a source of calcium to mineralize an immature or demineralized enamel surface. Choice C is correct as calcium and phosphate in saliva do provide a buffering action to protect teeth from acids.
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Which of the following foods provides the most protein?
- A. Beans
- B. Red peppers
- C. Asparagus
- D. Celery
Correct Answer: A
Rationale: The correct answer is A, Beans. Beans are known to be a good source of protein compared to the other options provided. While red peppers, asparagus, and celery are nutritious vegetables, they do not contain as much protein as beans do. Red peppers are high in vitamin C, asparagus is rich in vitamins and minerals, and celery is low in calories and a good source of fiber, but they are not significant sources of protein.
The RDA for iron is higher in premenopausal women than for men or postmenopausal women because of the blood loss during menstruation.
- A. Both the statement and the reason are correct and related.
- B. Both the statement and the reason are correct but are not related.
- C. The statement is correct, but the reason is not correct.
- D. The statement is not correct, but the reason is correct.
Correct Answer: A
Rationale: Both the statement and the reason are correct and related. The Institute of Medicine (IOM) recommends 18 mg of iron per day for women 19 to 50 years old, 8 mg/day for women 51 years old and older, and men 19 years old and older. During menstruation, women lose blood containing iron, leading to a higher iron requirement in premenopausal women compared to men or postmenopausal women. This increased demand aims to replenish the iron lost during this physiological process. Therefore, the statement and reason are directly linked, explaining why the RDA for iron is higher in premenopausal women than in men or postmenopausal women. Choices B, C, and D are incorrect as they do not accurately assess the relationship between the statement and the reason provided in the question.
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.
Which consumption pattern of fermentable carbohydrate is considered most cariogenic?
- A. A single exposure to a large quantity
- B. A single exposure to a small quantity
- C. Multiple exposures of small quantities
- D. Multiple exposures followed by chewing sugarless gum
Correct Answer: C
Rationale: Multiple exposures of small quantities are considered most cariogenic. The total amount of dietary fermentable carbohydrate seems to matter less than the form and frequency in which it is consumed. Having multiple exposures of even small quantities of fermentable carbohydrate throughout the day promotes a highly cariogenic environment in the mouth. Choices A and B, involving single exposures, are less cariogenic as they do not sustain the fermentation process over time. Choice D suggests a beneficial practice by chewing sugarless gum after exposures, which can reduce the risk, making it less cariogenic compared to multiple exposures of small quantities.
Wernicke-Korsakoff syndrome is associated with which vitamin deficiency?
- A. Thiamine (B1)
- B. Riboflavin (B2)
- C. Niacin (B3)
- D. Pyridoxine (B6)
Correct Answer: A
Rationale: Wernicke-Korsakoff syndrome is indeed associated with thiamine (vitamin B1) deficiency. This syndrome is commonly seen in individuals with chronic alcoholism due to poor diet and impaired thiamine absorption. Thiamine is essential for normal brain function and energy metabolism. Riboflavin (B2) deficiency can lead to symptoms like sore throat and swollen mucous membranes, not Wernicke-Korsakoff syndrome. Niacin (B3) deficiency causes pellagra, characterized by dermatitis, diarrhea, dementia, and death, but not Wernicke-Korsakoff syndrome. Pyridoxine (B6) deficiency can result in dermatitis, glossitis, and peripheral neuropathy, but it is not associated with Wernicke-Korsakoff syndrome.