microbiology a systems approach test bank

Correct Answer: D

Rationale: The correct answer is D: eubiosis. Eubiosis refers to a state of balance and harmony among the species in the normal microflora. This term signifies a healthy and stable microbial community. Dysbiosis (A) is the opposite, indicating an imbalance or disruption in the microflora. Eukaryota (B) refers to organisms with cells containing a nucleus, not specifically related to the balance of microflora. Dispersion (C) refers to the spreading or distribution of microorganisms, not specifically related to their balance. In summary, eubiosis best describes the dynamic balance of species in the normal microflora, making it the correct choice.

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: Rationale: - A: The mycelium is indeed made up of intertwined hyphae, which are the branching filaments of fungi. - B: Part of the mycelium does grow into the medium to acquire nutrients, forming the substrate mycelium. - C: Some parts of the mycelium remain above the medium to aid in reproduction and spore dispersal, forming the aerial mycelium. Therefore, all statements (A, B, and C) are correct, making choice D the correct answer. The mycelium exhibits both intertwined hyphae, substrate mycelium, and aerial mycelium to facilitate different functions.

Correct Answer: A

Rationale: The correct answer is A: Reinfection. This is because the patient fully recovered from the initial syphilis infection after antibiotic therapy, indicating the elimination of the pathogen. Subsequently getting infected again with Treponema pallidum suggests a new exposure to the same pathogen, resulting in a new infection. Recurrence (B) would imply the reactivation of the same infection, which is not the case here. Superinfection (C) refers to a new infection that occurs on top of an existing infection, which is not the scenario described. Secondary infection (D) typically refers to an infection that occurs after an initial infection weakens the immune system, which is not the case in this scenario.

Correct Answer: C

Rationale: The correct answer is C: 10% of the infected men have no symptoms. This is true because gonorrhea can be asymptomatic in some individuals, leading to undiagnosed cases. Testicular pain and epididymal tenderness (choice A) are not typical symptoms of gonorrhea in men. Painful urination (choice B) may or may not be present. Purulent discharge (choice D) is a common symptom but not always present. Therefore, choice C is the most accurate statement regarding gonorrhea symptoms in men.