Muscarinic agonist used for atonic bowel or bladder:

Correct Answer: C

Rationale: Certainly! Bethanechol is a muscarinic agonist that specifically targets the bladder and bowel smooth muscles, improving their tone and contractility. It is used for conditions like atonic bowel or bladder dysfunction. Clonidine is an alpha-2 adrenergic agonist, Chlorpromazine is a typical antipsychotic, and Ephedrine is a sympathomimetic amine used for decongestion and bronchodilation. These medications do not have the same mechanism of action or target as Bethanechol and are not indicated for atonic bowel or bladder issues.

Correct Answer: C

Rationale: The correct answer is C: Propranolol. Verapamil is a calcium channel blocker that can depress heart rate and contractility. Propranolol is a beta-blocker that also decreases heart rate and contractile force. When combined, both drugs can have an additive effect leading to a significant decrease in heart rate and contractility, potentially causing bradycardia or heart failure. Albuterol (A) is a beta-2 agonist that actually increases heart rate and contractility. Scopolamine (B) is an anticholinergic drug that may decrease heart rate, but its effect is not as significant as propranolol. Isoproterenol (D) is a beta agonist that increases heart rate and contractility, so its combination with verapamil would not pose the same risk as propranolol.

Correct Answer: C

Rationale: The correct answer is C because active transport involves the movement of particles from low concentration to high concentration, which goes against the natural flow of diffusion and requires energy input. In active transport, cells use ATP to pump substances across the cell membrane against their concentration gradient. This process allows cells to accumulate essential molecules or ions that are needed in higher concentrations inside the cell. Choices A, B, and D all describe passive transport processes where particles move with the concentration gradient and do not require energy input.

Correct Answer: A

Rationale: The correct formula for aluminium sulfate is Al2(SO4)3. This is because aluminium has a 3+ charge while sulfate has a 2- charge, requiring two aluminium ions to balance three sulfate ions. Choice B (Al2(SO3)4) is incorrect because sulfate ions have a 2- charge, not sulfite ions (SO3). Choices C (Al4(SO4)2) and D (Al4(SO3)2) have incorrect subscripts for the elements, not following the correct charge balance.

Correct Answer: D

Rationale: The correct answer is D: 2.0, sinks. Density is calculated by mass/volume. If the density of the block is 2.0, it means it is denser than the liquid (density of water is around 1.0), so it will sink. If the density was 0.50, it would be less dense than the liquid and float, making choices A and C incorrect. Choice B is also incorrect as a block with a density of 0.50 would float.