Adrenaline is NOT given orally because:

Correct Answer: D

Rationale: The correct answer is D: All of the above. Adrenaline is not given orally because: A) It is inactivated in the gut mucosa due to enzymatic breakdown, B) Local vasoconstriction inhibits absorption into the bloodstream, and C) It is rapidly inactivated in circulation by enzymes like catechol-O-methyltransferase and monoamine oxidase. Therefore, administering adrenaline orally would result in poor absorption and rapid degradation, making it ineffective.

Correct Answer: A

Rationale: Rationale: Atropine is the correct answer as it is an anticholinergic agent like propantheline, both inhibiting acetylcholine activity. This action reduces gastric acid secretion, aiding in peptic ulcer treatment. Neostigmine (B) increases acetylcholine activity, opposite to propantheline's effect. Propranolol (C) is a beta-blocker, not directly affecting gastric acid secretion. Phentolamine (D) is an alpha-blocker, also not related to reducing gastric acid secretion.

Correct Answer: B

Rationale: The correct answer is B: Only some bacteria will be killed by some antibiotics. Antibiotic resistance refers to the ability of bacteria to survive and grow despite the presence of an antibiotic. This occurs when bacteria evolve and develop mechanisms to defend against antibiotics. It is not accurate to say that no bacteria will be killed by any antibiotic (choice A) as some bacteria may still be susceptible to certain antibiotics. Antibiotics are not effective against viruses, so choice C and D are incorrect. In summary, antibiotic resistance specifically pertains to bacteria developing the ability to survive some antibiotics, making choice B the correct answer.

Correct Answer: B

Rationale: The correct answer is B: neutralisation, yellow. In a neutralization reaction between an acid and a base, the acidic and basic properties neutralize each other, resulting in a salt and water. The indicator phenolphthalein is commonly used in acid-base titrations, turning pink in basic solutions and colorless in acidic solutions. When the reaction is complete and the solution is neutral (pH 7), phenolphthalein appears yellow. Therefore, the color of the mixture at the end of a neutralization reaction is yellow. Choices A, C, and D are incorrect because neutralization reactions typically result in a yellow color, not orange, and redox reactions do not involve the same color changes as neutralization reactions.

Correct Answer: D

Rationale: The correct answer is D. In circuit symbols, a heater is typically represented by a zigzag line enclosed in a rectangle. This symbol signifies the generation of heat through resistance. Option A does not resemble a heater symbol, Option B is a resistor symbol, and Option C is a light bulb symbol. Therefore, the correct answer is D as it accurately represents a heater in circuit diagrams.