microbiology an introduction 12th edition test bank

Correct Answer: D

Rationale: The correct answer is D (All of the above) because different bacteria can cause pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Mycobacterium tuberculosis causes tuberculosis, which can lead to pneumonia. Pseudomonas aeruginosa is a common cause of hospital-acquired pneumonia. Therefore, all three bacteria can be responsible for causing pneumonia in different contexts. Choices A, B, and C are incorrect because each bacterium individually can cause pneumonia, so selecting only one option would not cover the full spectrum of bacterial causes of pneumonia.

Correct Answer: A

Rationale: The correct answer is A: Pili. Pili are hair-like appendages on the surface of bacteria that facilitate the exchange of genetic material through a process called conjugation. During conjugation, bacteria can transfer plasmids and other genetic material to neighboring bacteria through pili. This allows for the exchange of beneficial traits like antibiotic resistance. Choice B, Flagella, are involved in bacterial movement and not in genetic material exchange. Choice C, Endospores, are protective structures formed by bacteria in response to harsh conditions, but they are not involved in genetic material exchange. Choice D, Capsules, are protective layers around bacteria that help in adherence to surfaces and evasion of the immune system, but they do not play a role in genetic material exchange.

Correct Answer: A

Rationale: The correct answer is A because a soft chancre is a type of sexually transmitted infection caused by the bacterium Haemophilus ducreyi. It presents as a painless ulcer on the genitals. The other choices are incorrect. B is incorrect because STIs can enter the body through various routes, not only the urogenital tract mucosa. C is incorrect because immunity to syphilis is not lifelong; reinfection is possible. D is incorrect because STIs can occur in any country regardless of social status or hygiene levels.

Correct Answer: A

Rationale: The Ascoli precipitation test is specifically used to detect anthrax agent antigens. The test involves mixing a patient's serum with a solution containing anthrax antigens, leading to precipitation if the antigens are present. Therefore, a positive reaction in this test indicates the presence of anthrax agent antigens. The other choices (B: Brucellosis agent, C: Anaerobic infection toxin, D: Plague agent) are incorrect because the Ascoli precipitation test is not designed to detect these specific agents or toxins.

Correct Answer: B

Rationale: The correct answer is B: It causes epidemic meningitis. Neisseria Meningitidis is a bacterium that can cause meningitis, an infection of the protective membranes covering the brain and spinal cord. This bacterium is known to cause outbreaks or epidemics of meningitis, especially in crowded or close-contact settings. The other choices are incorrect because: A: Neisseria Meningitidis does have a capsule, which helps it evade the immune system. C: Neisseria Meningitidis grows on selective media like Thayer-Martin agar, not differential media. D: Neisseria Meningitidis is a Gram-negative diplococcus, not a Gram-positive rod.