microbiology chapter 13 test bank

Correct Answer: A

Rationale: The correct answer is A: germination. In the lytic life cycle of phages, germination is not a stage. The lytic cycle involves adsorption, penetration, replication, assembly, and lysis. Germination is typically associated with the lysogenic cycle, where the phage DNA integrates into the host genome. Therefore, A is the correct answer. Choices B, C, and D are incorrect because they are all stages of the lytic cycle. Penetration refers to the injection of phage DNA into the host cell, adsorption is the attachment of the phage to the host cell, and lysis is the final stage where the host cell bursts, releasing new phages.

Correct Answer: C

Rationale: The correct answer is C: orphan drugs. Orphan drugs are medications developed to treat rare diseases affecting fewer than 200,000 patients. These diseases often lack attention from pharmaceutical companies due to the high cost and limited market potential. Orphan drugs receive special incentives and regulatory support to encourage their development. A: Secondary drugs do not specifically refer to medications for rare diseases. B: Minor drugs is not a recognized term in the context of rare disease medications. D: Specialty drugs typically refer to high-cost medications used to treat complex or chronic conditions, but not necessarily rare diseases.

Correct Answer: A

Rationale: The correct answer is A: Neisser staining method. Neisser staining method is used to stain diphtheria bacilli, which appear as blue rods with thickenings at the poles. The rationale is that Neisser staining specifically targets and highlights the characteristics of the diphtheria bacilli. Incorrect choices: B: Gram staining is not specific for diphtheria bacilli and does not show the characteristic blue rods with thickenings at the poles. C: Ziehl-Neelsen staining is used for acid-fast bacteria like Mycobacterium tuberculosis, not for diphtheria bacilli. D: Loeffler staining is used for diphtheria bacilli but does not produce blue rods with thickenings at the poles as seen in this case.

Correct Answer: C

Rationale: The correct answer is C because Rickettsia requires living cells for growth and replication. Chick embryos, cell cultures, and lab animals provide a suitable environment for Rickettsia isolation. Skin-allergy tests (A) and serological methods for proving antibodies (B) are not directly used for isolating Rickettsia as they do not support the growth of the bacteria. "None of the above" (D) is incorrect as option C involves the appropriate methods for isolating Rickettsia.

Correct Answer: B

Rationale: The correct answer is B: Capsule. Capsules are a protective layer outside the bacterial cell wall that helps bacteria evade phagocytosis by immune cells. The capsule inhibits phagocytic cells from engulfing the bacteria, making it difficult for them to be recognized and destroyed. A: Flagella - Flagella are not involved in protecting bacteria from phagocytosis. They are responsible for bacterial movement. C: Endospore - Endospores are dormant, resistant structures formed by some bacteria in response to harsh conditions. They do not directly protect against phagocytosis. D: Pili - Pili are hair-like structures used for adhesion and conjugation, not for protection against phagocytosis.