medical microbiology test bank

Correct Answer: C

Rationale: Step 1: Define sexually transmitted infections (STIs) as infections primarily spread through sexual contact. Step 2: Understand that STIs can also be transmitted through non-sexual means like blood transfusions. Step 3: Recognize that choice C is incorrect as it limits STIs to only sexually transmitted infections. Step 4: Therefore, the correct answer is C as it does not encompass all possible modes of transmission for STIs. Summary: Choices A, B, and D are incorrect as they all accurately describe the characteristics of sexually transmitted infections, while choice C is incorrect as it excludes other potential modes of transmission for STIs.

Correct Answer: A

Rationale: The correct answer is A: Rifampicin. Rifampicin can cause red-orange discoloration of bodily fluids like urine due to its metabolism. This phenomenon is harmless but alarming to patients. Isoniazid (B) can cause peripheral neuropathy, Pyrazinamide (C) can cause hyperuricemia, and Ethambutol (D) can cause optic neuropathy.

Correct Answer: C

Rationale: The correct answer is C because transcription is the process in which messenger RNA transcripts are produced from DNA. During transcription, a specific segment of DNA is transcribed into mRNA by RNA polymerase. Choice A is incorrect because translation, not transcription, involves converting mRNA into protein. Choice B is incorrect as it describes DNA replication, not transcription. Choice D is incorrect because it refers to translation, where polypeptides are synthesized from mRNA. Therefore, choice C is the correct answer as it accurately describes the process of transcription.

Correct Answer: D

Rationale: The correct answer is D because fungi do not form flagella. Fungi reproduce sexually and asexually (A) through spores, have a cell wall (B) made of chitin, and are mostly aerobic or facultative anaerobes (C). Flagella are structures found in some protozoa and bacteria, not in fungi. Therefore, option D is the only statement that is not true about fungi.

Correct Answer: A

Rationale: Rationale: 1. Dysenteric amoeba (Choice A) is the correct answer because it can exist asymptomatically in carriers and be transmitted through cysts. 2. Malarial plasmodium (Choice B) causes malaria, not carried asymptomatically in cysts. 3. Intestinal trichomonad (Choice C) causes trichomoniasis, not carried asymptomatically in cysts. 4. Dermatotropic leishmania (Choice D) causes skin lesions, not carried asymptomatically in cysts.