foundations in microbiology test bank

Correct Answer: A

Rationale: The correct answer is A: Trichomonas vaginalis. Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes trichomoniasis, characterized by foamy purulent vaginal discharges. Microscopy of vaginal discharge showing flagellated protozoa with an undulating membrane and pear-shaped structure is indicative of Trichomonas vaginalis. Trypanosoma gambiense causes African sleeping sickness and is transmitted by tsetse flies. Leishmania donovani causes visceral leishmaniasis transmitted by sandflies. Lamblia intestinalis causes giardiasis and is characterized by diarrhea and flatulence.

Correct Answer: B

Rationale: The correct answer is B: All are correct. Candida albicans can cause skin infections such as candidiasis. Staphylococcus aureus and Streptococcus pyogenes are common bacteria that can also cause skin infections. Therefore, choice B is correct as all three microorganisms listed can cause skin infections. Choices A, C, and D are incorrect because individually, each of the microorganisms listed can cause skin infections.

Correct Answer: A

Rationale: The correct answer is A: Isoniazid. Isoniazid is known to cause peripheral neuropathy as a side effect, especially with prolonged use. It can lead to symptoms such as numbness, tingling, and weakness in the toes and fingers due to its neurotoxic effects. Rifampicin (B) is less likely to cause neuropathy. Ciprofloxacin (C) is not typically associated with neuropathy. Sodium salt of benzylpenicillin (D) is an antibiotic but is not known to cause polyneuritis.

Correct Answer: D

Rationale: The correct answer is D because smallpox vaccination provides long-lasting immunity, often for a lifetime. Revaccination is not necessary as the initial vaccine confers sufficient protection. Choice A is incorrect because yearly revaccination is unnecessary and excessive. Choice B and C are also incorrect as there is no need for revaccination every second or third year. The key is to understand that smallpox vaccination typically provides lifelong immunity, making ongoing revaccination unnecessary.

Correct Answer: A

Rationale: Osmosis is the correct answer because it is the process by which water molecules move across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. This movement occurs passively, driven by the concentration gradient. Facilitated diffusion (B) involves the transport of specific molecules with the help of carrier proteins, not water. Phagocytosis (C) is a process where cells engulf solid particles, not water molecules. Exocytosis (D) is the process of releasing substances from a cell by fusion of vesicles with the cell membrane, not the transport of water across the membrane.