Correct Answer: D

Rationale: The correct answer is D, chromoblastomycosis. This is a chronic localized subcutaneous infection caused by certain fungi, resulting in verrucoid lesions on the skin. The other choices are incorrect because: A: Candidiasis is a superficial fungal infection, not characterized by verrucoid lesions. B: Leprosy is a systemic bacterial infection, not localized to the skin with verrucoid lesions. C: Shingles is caused by the varicella-zoster virus, presenting as a painful rash with blisters, not verrucoid lesions.

Correct Answer: A

Rationale: The correct answer is A: protein envelope around the nucleic acid. Viral capsid is the protein coat that surrounds and protects the viral nucleic acid (DNA or RNA). This structure helps in protecting the genetic material from degradation and facilitates the attachment of the virus to host cells. Option B is incorrect as it suggests the nucleic acid is coated with protein, which is not the case. Option C is incorrect as not all viruses have an outer membrane. Option D is incorrect as viruses typically do not have a lipoprotein membrane.

Correct Answer: A

Rationale: Step 1: Treponema pallidum is a spirochete bacterium known to cause syphilis, a sexually transmitted infection. Step 2: Neisseria gonorrhoeae causes gonorrhea, not syphilis. Step 3: Chlamydia trachomatis is responsible for causing chlamydia, not syphilis. Step 4: Escherichia coli is commonly found in the gut and can cause gastrointestinal infections, not syphilis. Summary: Treponema pallidum is the correct answer as it is the specific bacterium associated with syphilis, while the other choices are responsible for different infections.

Correct Answer: B

Rationale: The correct answer is B (Urethra). Resident microflora are typically found in various parts of the body where they establish a stable population without causing harm. The urethra is one of the locations where resident microflora are commonly present, helping to maintain a healthy microbial balance and prevent pathogenic bacteria from colonizing the area. In contrast, choices A, C, and D are not typical locations for resident microflora. Blood is normally sterile, the lungs have a different microbial environment due to their exposure to the external environment, and the cerebro-spinal fluid is also typically sterile to prevent infections in the central nervous system.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Poxviruses are indeed the largest viruses known, ranging from 200-450 nm in size, which is close to the resolution limit of a light microscope. This makes them almost visible under a light microscope. Explanation: 1. Poxviruses have complex structures and are among the largest viruses. 2. Light microscopes have a resolution limit of around 200 nm. 3. Poxviruses fall within the size range that is close to the resolution limit of a light microscope. 4. Therefore, poxviruses are almost visible under a light microscope. Summary: Choice B is incorrect because poxviruses are indeed large enough to be almost visible under a light microscope. Choice C is incorrect as it implies uncertainty, but poxviruses are consistently close to the resolution limit of a light microscope. Choice D is incorrect as the size of poxviruses being almost visible under a light microscope is a factual statement, not dependent