microbiology an introduction test bank

Correct Answer: B

Rationale: The correct answer is B (2). During glycolysis, one glucose molecule is broken down into two molecules of pyruvate. In this process, a net gain of 2 ATP molecules is produced through substrate-level phosphorylation. Specifically, ATP is generated during the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate and during the conversion of phosphoenolpyruvate to pyruvate. The other choices are incorrect because the net gain of ATP molecules in glycolysis is not 1, 3, or 4; it is 2 based on the specific enzymatic reactions involved in the pathway.

Correct Answer: A

Rationale: The correct answer is A: Streptococcus pneumoniae. The presence of Gram-positive cocci in pairs with a capsule is characteristic of Streptococcus pneumoniae. Step 1: Gram-positive cocci in pairs indicate a Streptococcus species. Step 2: The presence of a capsule suggests S. pneumoniae specifically. Summary: B: Staphylococcus aureus is a Gram-positive cocci but does not typically present in pairs with a capsule. C: Neisseria gonorrhoeae is a Gram-negative diplococcus, not a Gram-positive cocci. D: Klebsiella pneumoniae is a Gram-negative rod, not a cocci.

Correct Answer: D

Rationale: The correct answer is D (A and B both). In viral multiplication, the presence of a specific cytopathic effect (CPE) in cell culture indicates viral replication. This is detected visually through changes in cell morphology. Additionally, immunofluorescence detection methods can be used to detect viral antigens within infected cells, confirming viral multiplication. Options C is incorrect as viral colonies are not typically used to detect viral multiplication in cell culture. Option B alone is not sufficient as it only focuses on immunofluorescence detection, while option A alone may not always be specific. Therefore, the combination of A and B provides a more comprehensive and accurate detection method for viral multiplication in cell culture.

Correct Answer: C

Rationale: The correct answer is C: Bacterial adhesion to the surface of the host cells, conjugation. Villi and cilia on the cell surface of pathogenic bacteria help in bacterial adhesion to host cells, facilitating the process of infection. Conjugation is the transfer of genetic material between bacterial cells, which can be aided by these structures. The other choices are incorrect because RNA exchange between cells (A) is typically facilitated by different structures like pili, inhibition of complement activity (B) is not related to the function of villi and cilia, and resistance to antibody opsonization (D) is usually achieved through other mechanisms such as capsule formation.

Correct Answer: A

Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is a gram-negative bacterium known for its green-blue pigmentation and sweet, fruity odor. The large colorless mucous colonies that develop green-blue pigmentation and honey or jasmine smell point towards Pseudomonas aeruginosa. The bacterioscopy revealing gram-negative lophotrichea further supports this identification. Proteus vulgaris and Klebsiella osaenae do not typically exhibit the described characteristics. Streptomyces griseus is a soil bacterium known for its antibiotic production and is not commonly associated with wound infections.