In a compound light microscope the lens closest to the eye is the __________ lens.

Correct Answer: A

Rationale: The correct answer is A: ocular lens. The ocular lens is the lens closest to the eye in a compound light microscope. This lens is responsible for magnifying the image produced by the objective lens. It typically has a magnification power of 10x. The objective lens, choice B, is positioned closer to the specimen and provides the primary magnification of the image. The condenser, choice C, is located beneath the stage and helps focus light onto the specimen. The stage, choice D, is where the specimen is placed for observation. Therefore, the ocular lens is the correct choice as it is the lens closest to the eye and responsible for further magnifying the image.

Correct Answer: C

Rationale: The correct answer is C: Granuloma formation. In response to tuberculosis antigen (tuberculin), the immune system forms a granuloma at the injection site as a defense mechanism. Granulomas are organized collections of immune cells that wall off the antigen and prevent its spread. This process involves macrophages, T cells, and fibroblasts. Choice A (Cells cytotoxity) is incorrect because tuberculin test does not involve direct cell cytotoxicity. Choice B (Reagin type cytotoxity) is incorrect as reagin type hypersensitivity is associated with allergic reactions, not granuloma formation. Choice D (Immunocomplex cytotoxity) is also incorrect as immunocomplex cytotoxicity refers to tissue damage caused by immune complexes, not granuloma formation.

Correct Answer: B

Rationale: The correct answer is B: Leptospirosis. Spiral-shaped bacteria with loose coils and pointed ends are characteristic of Leptospira interrogans, the causative agent of Leptospirosis. This bacterium is typically found in contaminated water or soil and can infect humans through contact with infected animals or water. Syphilis (Choice A) is caused by the spirochete Treponema pallidum, which has a more tightly coiled shape and does not typically appear loose or pointed. Relapsing fever (Choice C) is caused by Borrelia species, which are also spirochetes but do not have the loose coils and pointed ends described. Lyme disease (Choice D) is caused by Borrelia burgdorferi, which, like Relapsing fever, does not match the morphology described.

Correct Answer: B

Rationale: The correct answer is B: Diarrhea. Brucellosis typically presents with symptoms such as arthralgia, headache, and undulating fever, but diarrhea is not a common symptom associated with the disease. Brucellosis is primarily characterized by systemic symptoms like fever, joint pain, and headache due to the bacterial infection. Diarrhea is more commonly seen in gastrointestinal infections rather than brucellosis. Therefore, the absence of diarrhea as a symptom in brucellosis helps in differentiating it from other diseases with similar clinical presentations.

Correct Answer: A

Rationale: 1. Gram-positive cocci in clusters suggest Staphylococcus species. 2. Catalase-positive and coagulase-positive characteristics match with Staphylococcus aureus. 3. Staphylococcus aureus is a common cause of wound infections due to its virulence factors. 4. Other choices are incorrect: B) S. epidermidis is coagulase-negative and a common contaminant, C) S. pyogenes is catalase-negative, D) Enterococcus faecalis is not typically associated with wound infections.