Correct Answer: A

Rationale: The correct answer is A, Salivary amylase. Salivary amylase is an enzyme produced by the parotid gland that initiates starch digestion in the mouth. It helps break down starch into maltose, a simpler sugar. Choices B, C, and D are incorrect because sucrase, maltase, and lactase are enzymes involved in the digestion of disaccharides like sucrose, maltose, and lactose, respectively, in the small intestine, not in the saliva.

Correct Answer: B

Rationale: Lignin is the correct answer because it is a type of fiber that is not a carbohydrate and provides structure to plant cell walls. Gums (choice A), pectin (choice C), and cellulose (choice D) are all types of dietary fiber that are carbohydrates. Gums are a type of soluble fiber, pectin is found in fruits and is a soluble fiber, and cellulose is a type of insoluble fiber found in plant cell walls.

Correct Answer: C

Rationale: The correct answer is C. Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds. Therefore, the number of double bonds is the chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid. Choices A, B, and D are incorrect because the distinguishing factor between saturated and unsaturated fatty acids lies in the presence or absence of double bonds, not in the arrangement of carbon atoms, number of oxygen molecules, or food source.

Correct Answer: C

Rationale: Fat provides 9 kcal per gram, so 35 grams of fat provides 315 kcal. Therefore, the correct answer is C. Choice A (140) is incorrect because it doesn't consider the energy content of fat. Choice B (245) is incorrect as it miscalculates the kilocalories provided by 35g of fat. Choice D (360) is incorrect because it overestimates the kilocalories provided by 35g of fat.

Correct Answer: D

Rationale: Prevident is indicated for all the situations listed in the choices. It is recommended for patients with a high risk of caries to reduce the risk of tooth decay. It is also used in dental procedures like crown and bridge work to strengthen enamel and prevent cavities. Furthermore, it is utilized for orthodontic decalcification to aid in remineralizing the tooth structure and prevent further damage. Therefore, the correct answer is 'All of the above.' While choices A, B, and C are individually correct, selecting 'All of the above' is the most appropriate as it encompasses all the possible indications for Prevident.