Microbiology An Introduction 13th Edition Test Bank

Correct Answer: A

Rationale: The correct answer is A: Sabouraud. Sabouraud agar is specifically designed to promote the growth of fungi due to its low pH and high glucose content. The cream-like colonies indicate fungal growth, as fungi often appear as fluffy or powdery colonies on Sabouraud agar. Lowenstein-Jensen is used for mycobacteria, Roux for diphtheria, and Loeffler for Corynebacterium diphtheriae. Therefore, Sabouraud is the most suitable medium for detecting fungal contamination based on the characteristics of the colonies formed.

Correct Answer: C

Rationale: The bacterial capsule is composed of polysaccharides. This outer layer helps bacteria evade the host immune system, protect against desiccation, and aid in attachment to host cells. Polysaccharides are long chains of sugar molecules, providing a protective barrier for the bacteria. Lipopolysaccharides (choice A) are found in the outer membrane of Gram-negative bacteria and are not a major component of the capsule. Teichoic acid (choice B) is a component of the cell wall in Gram-positive bacteria, not the capsule. Peptidoglycan (choice D) is another component of the cell wall but is not part of the capsule.

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: The correct answer is A: A vaccine strain. Virus Fixe is a specific strain of rabies virus used in the production of rabies vaccines. This strain has been attenuated to be safe for use in vaccines. Choice B, a cell culture, is incorrect as it does not specifically refer to Virus Fixe. Choice C, a wild type of rabies virus, is incorrect as Virus Fixe is not a wild type but a modified strain. Choice D, an infectious disease, is incorrect as Virus Fixe is not a disease but a strain of virus used in vaccines.

Correct Answer: B

Rationale: The correct answer is B because a supercapsid is a lipoprotein membrane that encloses the nucleocapsid, providing protection to the genetic material inside. This structure is distinct from the capsid which is the protein coat surrounding the nucleic acid. Choice A is incorrect as there is no shell located between the capsid and supercapsid. Choice C is incorrect as it describes the nucleocapsid itself, not the supercapsid. Choice D is incorrect as a protein envelope around the nucleic acid does not specifically refer to a supercapsid.