Sickle cell disease is an example of an inherited mistake in the amino acid sequence.

Correct Answer: A

Rationale: The statement is TRUE. Sickle cell disease is caused by a genetic mutation in the hemoglobin gene, leading to an abnormal amino acid sequence. This results in the production of abnormal hemoglobin molecules, causing red blood cells to become sickle-shaped. This inherited condition is a classic example of a genetic error affecting the amino acid sequence, making choice A the correct answer. Choices B, C, and D are incorrect as they do not accurately reflect the nature of sickle cell disease.

Correct Answer: C

Rationale: The correct answer is C: bicarbonate ions. Bicarbonate ions, secreted by the pancreas, neutralize the acidic chyme entering the small intestine from the stomach, creating a more suitable environment for digestive enzymes. Saliva (choice A) helps in the initial breakdown of food in the mouth, not in neutralizing stomach acid. Gastric mucus (choice B) protects the stomach lining from the acidic environment but does not neutralize the acid in the small intestine. Enzymes (choice D) facilitate chemical reactions in digestion but do not neutralize stomach acid.

Correct Answer: D

Rationale: Type 2 diabetes is characterized by insulin resistance, high blood glucose levels, and high blood insulin levels. Rapid destruction of the pancreas is not a feature of this condition. The destruction of pancreatic beta cells is more commonly associated with type 1 diabetes, not type 2 diabetes. Therefore, option D is the correct answer. Options A, B, and C are all characteristic features of type 2 diabetes, making them incorrect choices.

Correct Answer: D

Rationale: The correct answer is 'none of the above.' Human digestive enzymes like salivary amylase and pancreatic amylase cannot digest fiber. Instead, fiber is fermented by gut bacteria in the large intestine. Cellulase, which is an enzyme produced by some animals and microorganisms, can break down cellulose found in plants, but it is not a human digestive enzyme, making it an incorrect choice in this context.

Correct Answer: D

Rationale: Vitamin E is an antioxidant commonly found in sources like vegetable oils, nuts, seeds, and green leafy vegetables. It plays a crucial role in protecting cells from damage. Choices A and B are incorrect as Vitamin E is not produced by bacteria in the GI tract nor synthesized by sunlight exposure. Choice C is incorrect as beriberi is a deficiency of Vitamin B1 (thiamine), not Vitamin E.