Bacteristatic effect is:

Correct Answer: A

Rationale: The correct answer is A: Inhibition of bacterial cell division. Bacteriostatic effect refers to the ability to inhibit the growth and reproduction of bacteria without necessarily killing them. By inhibiting bacterial cell division, it prevents the bacteria from multiplying and causing further infection. This is different from choice B as it specifically targets cell division rather than just growth. Choice C is incorrect as it describes bactericidal effect, which involves destroying bacterial cells. Choice D is unrelated as bacterial L-forms are a specific type of bacterial cell variant, not related to bacteriostatic effect.

Correct Answer: A

Rationale: The correct answer is A: Levamisole. Levamisole blocks acetylcholine transmission at the myoneural junction of helminthes by inhibiting cholinesterase enzyme. This leads to paralysis and expulsion of the parasites from the host. Mebendazole (B) works by inhibiting microtubule synthesis in helminthes. Piperazine (C) causes paralysis by hyperpolarizing the helminth's muscle cells. Niclosamide (D) disrupts the helminth's energy metabolism. Therefore, Levamisole is the correct choice for blocking acetylcholine transmission specifically.

Correct Answer: B

Rationale: The correct answer is B: Cisplatin. Cisplatin is an anticancer drug belonging to inorganic metal complexes. It contains the metal platinum, which forms coordination complexes that interfere with DNA repair mechanisms in cancer cells, leading to cell death. Dacarbazine (A) is an organic compound, not an inorganic metal complex. Methotrexate (C) is a folate antagonist and Vincristine (D) is a vinca alkaloid, both are organic compounds unrelated to inorganic metal complexes. Thus, B is the correct choice for an anticancer drug belonging to inorganic metal complexes.

Correct Answer: B

Rationale: The correct answer is B: Adenosine. Adenosine is commonly used for treating supraventricular tachycardias, which can cause palpitations. It works by slowing electrical conduction in the heart, helping to restore normal heart rhythm. Mexiletine (A) is a sodium channel blocker used for ventricular arrhythmias. Sotalol (C) is a beta-blocker used for atrial and ventricular arrhythmias. Verapamil (D) is a calcium channel blocker used for atrial arrhythmias but not typically for palpitations due to supraventricular tachycardias.

Correct Answer: F

Rationale: The correct answer is B: Mexiletine. After administering amiodarone for atrial fibrillation and wide QRS, the next drug should target the wide QRS complex, indicating possible ventricular involvement. Mexiletine, a Class IB antiarrhythmic, is commonly used to treat ventricular arrhythmias. Lidocaine (A) is also a Class IB antiarrhythmic, but Mexiletine is preferred in this scenario due to its longer half-life. Phenytoin (C) is not indicated for atrial fibrillation or wide QRS. Nifedipine (D) is a calcium channel blocker and is not appropriate for treating ventricular arrhythmias.