A child visiting his grandfather at his farm returns home having fever, skin flush, dry mouth, constipation, dilated pupils, and increased heart rate. Which of the following could be the offending agent:

Correct Answer: A

Rationale: The correct answer is A: Eating seeds containing atropine. Atropine is a plant alkaloid commonly found in certain seeds that can cause symptoms such as fever, skin flush, dry mouth, constipation, dilated pupils, and increased heart rate when ingested. Atropine is known to have anticholinergic effects, which align with the symptoms presented by the child. Malathion (B) is an insecticide that typically causes different symptoms like nausea, vomiting, and diarrhea. Echothiophate drops (C) are cholinesterase inhibitors used in the treatment of glaucoma, which would not produce the described symptoms. Physostigmine (D) is a cholinesterase inhibitor that would not cause symptoms of anticholinergic toxicity seen in the child.

Correct Answer: B

Rationale: Step 1: Understand the question is about an alpha-blocker for hypertension. Step 2: Identify Prazosin as an alpha-blocker used for hypertension by blocking alpha-1 receptors. Step 3: Explain how Prazosin works to dilate blood vessels and lower blood pressure. Step 4: Summarize why other choices are incorrect: - A: Tyramine is not an alpha-blocker, it is found in certain foods. - C: Ergometrine is an ergot alkaloid used for uterine contractions, not hypertension. - D: Ergotamine is also an ergot alkaloid used for migraines, not hypertension.

Correct Answer: D

Rationale: The correct answer is D: Propranolol. Propranolol is a beta-blocker that blocks the beta-adrenergic receptors in the heart, preventing the reflex increase in heart rate caused by nitroglycerin. This action helps to counteract the potentially dangerous side effect of increased heart rate. A: Atropine is not the correct answer because it is an anticholinergic drug that increases heart rate, which would exacerbate the reflex cardiac stimulation caused by nitroglycerin. B: Cocaine is a stimulant drug that can further increase heart rate and is not used to inhibit reflex cardiac stimulation. C: Phentolamine is an alpha-blocker that primarily acts on alpha-adrenergic receptors and is not the preferred drug for inhibiting the reflex increase in heart rate caused by nitroglycerin.

Correct Answer: C

Rationale: The correct answer is C: Reduced blood pressure, hypotension. Quinidine's strong postsynaptic alpha-adrenergic receptor blocking activity would result in decreased activation of these receptors, leading to vasodilation and reduced blood pressure, which can cause hypotension. Choice A is incorrect because lacrimal and mucus secretions are not directly affected by alpha-adrenergic receptor blocking. Choice B is incorrect as dilated pupils are more associated with alpha-1 adrenergic receptor blockade. Choice D is incorrect as skeletal muscle tremors are not a typical side effect of alpha-adrenergic receptor blocking.

Correct Answer: D

Rationale: The correct answer is D because biodiversity refers to the variety of living organisms in an ecosystem, specifically the number of different species present. This term encompasses all forms of life, from bacteria to plants to animals. Choice A is incorrect as it only focuses on the increase in the number of species, not the overall diversity. Choice B is incorrect as it describes the interaction between organisms and their environment, not the diversity of species. Choice C is incorrect as it limits biodiversity to only animals, neglecting the importance of other living organisms in an ecosystem.