Hyoscine is one of the most effective drugs for preventing motion sickness, but may cause photophobia or blurred vision. Which is the most similar prototype drug?

Correct Answer: C

Rationale: Step 1: Hyoscine is an antimuscarinic drug used for motion sickness. Step 2: Atropine is a similar prototype drug as it also belongs to the antimuscarinic class. Step 3: Atropine, like hyoscine, can cause photophobia and blurred vision. Step 4: Monoamine oxidase inhibitors (A) are not related to antimuscarinic drugs. Step 5: Propranolol (B) is a beta-blocker and not an antimuscarinic drug. Step 6: Bethanechol (D) is a muscarinic agonist, opposite in action to antimuscarinic drugs like hyoscine and atropine.

Correct Answer: D

Rationale: Correct Answer: D Rationale: 1. Elements in the same group have similar outer electron configurations. 2. Outer-shell electrons determine chemical properties. 3. Having the same number of outer-shell electrons leads to similar chemical behaviors. 4. This is due to similar valence electron interactions in chemical reactions. Summary: A: Incorrect. Protons do not determine chemical properties in the same group. B: Incorrect. Neutrons do not affect chemical properties in the same group. C: Incorrect. Having the same number of electron shells does not guarantee similar chemical properties.

Correct Answer: D

Rationale: The correct answer is D: It is double-insulated. This is correct because double-insulated appliances have an extra layer of insulation for added safety, eliminating the need for a grounded connection. This feature protects users from electric shocks. Explanation for why the other choices are incorrect: A: It does not have a live connection - This is not necessarily true as appliances can have live connections depending on their design and function. B: It has two fuses - While some appliances may have fuses, the number of fuses does not determine the correctness of the statement about the appliance. C: It has two switches - The presence of two switches does not necessarily indicate the correctness of the statement about the appliance.

Correct Answer: D

Rationale: The correct answer is D: permissiveness. Permissiveness is when one hormone enables another hormone to fully exert its effects. The rationale is as follows: 1. Permissiveness allows a hormone to work effectively only when another hormone is present to "permit" its action. 2. Assertiveness (A) and antagonism (B) do not involve the requirement of another hormone for full effect. 3. Synergism (C) involves two hormones working together for a greater effect, but they can still exert some effect individually. In summary, permissiveness is the only option where a hormone cannot exhibit its full effect without the presence of another hormone.

Correct Answer: D

Rationale: Osteitis fibrosa cystica is caused by an increase in the parathyroid hormone (PTH). Elevated PTH levels lead to increased calcium release from bones, resulting in bone resorption and cyst formation. Other choices (A) calcitonin, (B) ADH, and (C) growth hormone do not directly impact calcium metabolism and bone resorption like PTH does.