ATI RN
microbiology an introduction test bank Questions
Question 1 of 5
Which of the statements below IS NOT CORRECT
Correct Answer: B
Rationale: The correct answer is B because live vaccines can potentially revert to a virulent form, although this is extremely rare. This is due to the live attenuated virus in the vaccine potentially mutating back to a more dangerous form. Live vaccines are designed to be weakened but there is a small risk of reversion. Therefore, statement B is not correct. A: This statement is correct as immunocompromised individuals may have adverse reactions to live vaccines due to their weakened immune system. C: This statement is correct as microbes with many serotypes can make it challenging to develop a vaccine that covers all variations. D: This statement is correct as side effects to vaccination, although usually mild and temporary, can occur in some individuals.
Question 2 of 5
A 19 year old woman suffers from primary syphilis. Doctor administered her complex therapy that includes benzylpenicillin sodium salt. What is the mechanism of action of this drug?
Correct Answer: A
Rationale: The correct answer is A. Benzylpenicillin sodium salt, also known as penicillin G, works by blocking the synthesis of peptidoglycan in the microbial cell wall. Peptidoglycan is crucial for the structural integrity of bacterial cell walls. By inhibiting its synthesis, penicillin disrupts the cell wall formation, leading to cell lysis and bacterial death. Choices B, C, and D are incorrect because penicillin does not target cytoplasm proteins, thiol enzymes, or RNA synthesis. Penicillin's primary mode of action is specifically related to interfering with bacterial cell wall synthesis.
Question 3 of 5
Gram staining is used to differentiate bacteria based on:
Correct Answer: C
Rationale: The correct answer is C: cell wall composition. Gram staining differentiates bacteria based on the structure of their cell walls. It classifies bacteria into Gram-positive (thick peptidoglycan layer) and Gram-negative (thin peptidoglycan layer). This differentiation is crucial for identifying bacterial species and guiding treatment choices. Size and shape (choice A) are not specific to Gram staining. Presence of flagella (choice B) is related to bacterial motility, not Gram staining. Genetic material (choice D) is not directly assessed by Gram staining. Overall, the unique composition of the cell wall is the key factor in distinguishing bacteria through Gram staining.
Question 4 of 5
Lysozyme acts on the bacterial:
Correct Answer: B
Rationale: The correct answer is B: cell wall. Lysozyme is an enzyme that targets the cell wall of bacteria by breaking down the peptidoglycan layer, leading to bacterial cell lysis. This action disrupts the structural integrity of the bacteria, ultimately causing their death. Choices A, C, and D are incorrect because lysozyme does not target the cytoplasm, nucleus, or capsule of bacteria. The primary function of lysozyme is to act on the cell wall, making option B the correct answer in this context.
Question 5 of 5
Which of the following viruses has the name of the city where it was first discovered:
Correct Answer: B
Rationale: Step-by-step rationale: 1. Marburg virus is named after the German city Marburg where it was first identified in 1967. 2. Chikungunya virus is named after a village in Tanzania. 3. Measles virus got its name from the Middle English word "maselen" meaning "many little spots". 4. Epstein-Barr virus is named after Michael Epstein and Yvonne Barr, who discovered it. Summary: B is correct as it is directly named after the city of its discovery. A, C, and D are incorrect as they are named after other locations, characteristics, or discoverers.