With regard to carbohydrate digestion:

Correct Answer: C

Rationale: Rationale for Correct Answer C: Oligosaccharidase deficiency leads to osmotic diarrhea because the incomplete breakdown of oligosaccharides in the small intestine results in unabsorbed sugars attracting water, causing diarrhea. This is a direct consequence of the deficiency in enzymes responsible for breaking down oligosaccharides. This is why Choice C is correct. Summary of Incorrect Choices: A: Salivary amylase works best at a neutral pH of around 6.7, not alkaline pH. B: Lactose intolerance is due to a deficiency in lactase enzyme, not related to carbohydrate digestion in the small intestine. D: Salivary amylase is inactivated in the acidic environment of the stomach, so it does not continue to digest carbohydrates there.

Correct Answer: A

Rationale: The correct answer is A: cAMP. cAMP, or cyclic adenosine monophosphate, does not release large amounts of energy on breakdown compared to the other choices. Here's the rationale: 1. ATP (Choice B) is known as the energy currency of the cell and releases a significant amount of energy when broken down. 2. Creatine phosphate (Choice C) is a high-energy compound that can rapidly donate its phosphate group to regenerate ATP. 3. ADP (Choice D) releases energy when converted to ATP through phosphorylation. 4. cAMP (Choice A) is a secondary messenger involved in signal transduction and does not store or release energy like ATP or creatine phosphate.

Correct Answer: B

Rationale: The correct answer is B because men lose about 0.6mg of iron per day through various physiological processes like shedding skin cells and hair. This loss must be replenished through dietary intake to maintain iron balance. Choice A is incorrect as iron is more readily absorbed in the ferrous form. Choice C is incorrect as the average daily iron intake is around 18mg. Choice D is incorrect ascorbic acid enhances iron absorption rather than reducing it.

Correct Answer: D

Rationale: The correct answer is D: Thyroid. The thyroid gland produces hormones T3 and T4, which regulate the body's metabolism, including the basal metabolic rate (BMR). These hormones play a crucial role in controlling how the body uses energy. The other choices, A: Parathyroid, B: Pancreas, and C: Testes, do not directly regulate BMR. Parathyroid regulates calcium levels, pancreas regulates blood sugar levels, and testes produce hormones related to male reproductive functions. Thyroid is the only gland among the choices that specifically controls BMR through its hormone production.

Correct Answer: C

Rationale: The correct answer is C: Mouth. Ingestion is the process of taking food or liquid into the body through the mouth. The mouth is responsible for chewing and breaking down food into smaller pieces, mixing it with saliva to start the digestion process. The stomach (A), small intestine (B), and large intestine (D) are not where ingestion takes place; they are involved in further digestion, absorption, and processing of nutrients. The mouth is the initial site of digestion and the starting point of the digestive process.