microbiology test bank

Correct Answer: C

Rationale: The correct answer is C: All microorganisms. Sterilization aims to eliminate all microorganisms, including pathogenic and non-pathogenic ones, to ensure complete absence of viable organisms. This is crucial in medical, laboratory, and food preparation settings to prevent contamination and spread of infections. Choices A and B are incorrect because sterilization does not differentiate between pathogenic and non-pathogenic microorganisms, aiming to eradicate all. Choice D is incorrect as sterilization does involve releasing subjects (microorganisms) using physical methods.

Correct Answer: B

Rationale: The correct answer is B: Motility. The bacterial flagellum is a whip-like appendage that helps bacteria move by rotating like a propeller. This motility allows bacteria to navigate their environment, find nutrients, and avoid harmful conditions. Choices A, C, and D are incorrect because the bacterial flagellum is not involved in protein synthesis, DNA replication, or spore formation. Protein synthesis occurs in ribosomes, DNA replication takes place in the nucleus or nucleoid, and spore formation is a specialized process involving the production of spores for survival in harsh conditions.

Correct Answer: A

Rationale: The correct answer is A: Entamoeba gingivalis. This organism matches the description provided in the question - unicellular with pseudopodia and ingested white blood cells, commonly found in dental plaque. Entamoeba gingivalis is known to inhabit the oral cavity and is associated with periodontal disease. Trichomonas vaginalis, Giardia lamblia, and Balantidium coli do not match the characteristics mentioned in the question and are not typically found in the oral cavity.

Correct Answer: D

Rationale: The correct answer is D: Binary fission. Binary fission is a method of bacterial cell division, not a method of acquiring genetic material. Transformation, conjugation, and transduction are mechanisms through which bacteria can acquire genetic material from other sources. Transformation involves the uptake of naked DNA from the environment, conjugation is the transfer of genetic material through direct cell-to-cell contact, and transduction is the transfer of genetic material via bacteriophages. Therefore, binary fission is the only option that does not involve the acquisition of new genetic material.

Correct Answer: D

Rationale: The correct answer is D: Oral candidiasis. Soor is a term used to describe oral candidiasis, a fungal infection caused by Candida species. This infection presents as white patches on the tongue, inner cheeks, and roof of the mouth. The other choices (A, B, C) refer to different types of fungal infections affecting various parts of the body, not specifically the oral cavity. Therefore, based on the description of soor and its characteristics, the correct answer is D.