ATI RN
microbiology a systems approach test bank Questions
Question 1 of 5
How do people get infected with diphtheria
Correct Answer: C
Rationale: The correct answer is C because diphtheria is primarily spread through respiratory droplets and physical contact with an infected person. The bacteria responsible for diphtheria is transmitted through coughing, sneezing, or sharing personal items. Swimming in contaminated water (A) does not spread diphtheria. Transmission (B) is a broad term and does not specifically address the mode of transmission for diphtheria. Contaminated food (D) is not a typical route of diphtheria transmission. Therefore, option C is the most accurate choice based on the known mode of transmission for diphtheria.
Question 2 of 5
Bacteria capable of growing at low temperatures are called:
Correct Answer: C
Rationale: The correct answer is C: psychrophiles. Psychrophiles are bacteria that can grow at low temperatures, typically below 20°C. This is because they have adapted to survive and thrive in cold environments. Mesophiles (A) grow best at moderate temperatures, thermophiles (B) thrive in high temperatures, and halophiles (D) prefer high salt concentrations. Psychrophiles are specifically adapted to cold temperatures, making them the correct choice in this scenario.
Question 3 of 5
Which of the following bacteria is responsible for causing syphilis?
Correct Answer: A
Rationale: Step 1: Treponema pallidum is a spirochete bacterium known to cause syphilis. Step 2: It is sexually transmitted and can cause various stages of disease. Step 3: Neisseria gonorrhoeae causes gonorrhea, not syphilis. Step 4: Chlamydia trachomatis causes chlamydia, not syphilis. Step 5: Escherichia coli is a common gut bacterium and not responsible for syphilis. Treponema pallidum is the correct answer as it is the specific bacterium known to cause syphilis.
Question 4 of 5
Family Retroviridae
Correct Answer: B
Rationale: The correct answer is B because retroviruses, including those in the Family Retroviridae, have a capsid consisting of two copies of single-stranded RNA (ssRNA). This is a defining characteristic of retroviruses, which use reverse transcriptase to convert their ssRNA into DNA. This DNA is then integrated into the host cell's genome. Choices A, C, and D are incorrect because Family Retroviridae viruses are not helical non-enveloped viruses (C), they are not helical enveloped viruses (A), and they do not have a complex type of symmetry (D).
Question 5 of 5
During the staining of sputum smear of a patient with suspected croupous pneumonia the following reactives and stainers were used: gentian violet solution, Lugol's solution, 960 spiritus and water fuchsin. What method of staining is used in this case?
Correct Answer: B
Rationale: The correct answer is B: Gram's staining method. The rationale for this is as follows: Gentian violet and Lugol's solution are used as primary and mordant stains in the Gram's staining method. Spiritus 960 is used as a decolorizer, and water fuchsin is used as a counterstain. This staining method is commonly used in microbiology to differentiate bacteria into Gram-positive and Gram-negative based on their cell wall characteristics. A: Leffler's staining method is used for the identification of diphtheria bacilli. C: Ziehl-Neelsen's staining method is used for acid-fast bacteria like Mycobacterium tuberculosis. D: Neisser's staining method is used for the identification of Neisseria species. In summary, the use of specific reactives and stainers in the question indicates the application of the Gram's staining method for bacterial differentiation.