ATI RN
microbiology chapter 13 test bank Questions
Question 1 of 5
Which of the following does NOT refer to viruses
Correct Answer: D
Rationale: The correct answer is D because viruses are sensitive to interferon, a natural defense mechanism of the body against viral infections. Interferon helps to inhibit viral replication.
A: Viruses are cell-free infectious particles, not living systems.
B: Viruses are obligate intracellular parasites as they require host cells to replicate.
C: Viruses can have either DNA or RNA as genetic material, which is a characteristic feature.
Question 2 of 5
N. Meningitidis grows on
Correct Answer: D
Rationale: The correct answer is D: Chocolate agar. Neisseria meningitidis is a fastidious organism that requires enriched media for growth. Chocolate agar contains heat-treated blood that provides essential nutrients for the growth of N. meningitidis. The other choices, A: Levine agar, B: Lowenstein-Jensen agar, and C: TCBS agar, do not provide the specific nutrients required for the growth of N. meningitidis.
Therefore, only choice D, Chocolate agar, supports the growth of N. meningitidis due to its enriched composition.
Question 3 of 5
A child is ill with diphtheria. A smear of the affected mucous membrane revealed blue rods with thickenings at the poles. What staining method was used?
Correct Answer: A
Rationale: The correct answer is A: Neisser staining method. Neisser staining method is used to stain diphtheria bacilli, which appear as blue rods with thickenings at the poles. The rationale is that Neisser staining specifically targets and highlights the characteristics of the diphtheria bacilli.
Incorrect choices:
B: Gram staining is not specific for diphtheria bacilli and does not show the characteristic blue rods with thickenings at the poles.
C: Ziehl-Neelsen staining is used for acid-fast bacteria like Mycobacterium tuberculosis, not for diphtheria bacilli.
D: Loeffler staining is used for diphtheria bacilli but does not produce blue rods with thickenings at the poles as seen in this case.
Question 4 of 5
Lytic life cycle of phages does not include
Correct Answer: A
Rationale: The correct answer is A: germination. In the lytic life cycle of phages, germination is not a stage. The lytic cycle involves adsorption, penetration, replication, assembly, and lysis. Germination is typically associated with the lysogenic cycle, where the phage DNA integrates into the host genome.
Therefore, A is the correct answer.
Choices B, C, and D are incorrect because they are all stages of the lytic cycle. Penetration refers to the injection of phage DNA into the host cell, adsorption is the attachment of the phage to the host cell, and lysis is the final stage where the host cell bursts, releasing new phages.
Question 5 of 5
For the structure of rubella virus, it is true that
Correct Answer: A
Rationale:
Step 1: Rubella virus belongs to the
Togaviridae family, which typically exhibits icosahedral symmetry.
Step 2: Icosahedral symmetry refers to a structure with 20 equilateral triangular faces, which is characteristic of many viruses, including rubella.
Step 3:
Therefore, choice A is correct as rubella virus indeed has icosahedral type of symmetry.
Summary:
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Choice B is incorrect as rubella virus is an ssRNA virus, not ssDNA.
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Choice C is incorrect as rubella virus does have an envelope derived from the host cell membrane.
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Choice D is incorrect as rubella virus does have glycoprotein spikes on its surface.