microbiology a systems approach test bank

Correct Answer: D

Rationale: The correct answer is D: All of the above. Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae are all bacteria associated with causing bacterial meningitis. Neisseria meningitidis commonly causes meningococcal meningitis, Haemophilus influenzae can cause H. influenzae type b meningitis, and Streptococcus pneumoniae is a common cause of pneumococcal meningitis. Therefore, all three bacteria are known to be causative agents of bacterial meningitis. The other choices are incorrect as they do not encompass all the bacteria associated with causing bacterial meningitis.

Correct Answer: A

Rationale: Step-by-step rationale for the correct answer (A - Clostridium tetani): 1. The patient has convulsive contractions of facial muscles, indicating tetanus. 2. Isolation of bacteria with terminal endospores that have a drumstick appearance is characteristic of Clostridium tetani. 3. Clostridium tetani produces tetanospasmin toxin causing muscle spasms. 4. Therefore, the correct answer is Clostridium tetani (A). Summary of why other choices are incorrect: B: Clostridium botulinum causes botulism, not tetanus. C: Clostridium perfringens causes gas gangrene, not tetanus. D: Bacillus anthracis causes anthrax, not tetanus.

Correct Answer: D

Rationale: Binary fission is the correct answer for bacterial replication because it is the process by which bacteria divide into two identical daughter cells. During binary fission, the bacterial cell replicates its DNA, forms a septum dividing the cell into two, and eventually splits into two daughter cells. This process is specific to prokaryotic cells such as bacteria and is different from mitosis and meiosis, which are processes specific to eukaryotic cells. Cytokinesis is the final step of cell division in both eukaryotes and prokaryotes, but it is not the primary mechanism of bacterial replication.

Correct Answer: D

Rationale: The correct answer is D because HIV can be transmitted from a mother to a child through multiple modes: during delivery through mixing of blood, during pregnancy through the placenta, and via breastmilk during lactation. Each mode presents a risk of transmission due to the presence of the virus in bodily fluids. Therefore, all of the above options are preferred modes of transmission for HIV from a mother to a child. Choices A, B, and C alone do not fully encompass all the possible routes of transmission, making them incorrect.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa are all known to cause urinary tract infections (UTIs) in humans. E. coli is the most common cause of UTIs, accounting for about 80-85% of cases. S. enterica and P. aeruginosa are less common but can still infect the urinary tract under certain circumstances. Therefore, all three bacteria can potentially cause UTIs, making option D the correct choice. Choices A, B, and C are incorrect because they do not cover the full range of bacteria known to cause UTIs.