ATI RN
foundations in microbiology test bank Questions
Question 1 of 9
The enzyme used by bacteria to break down hydrogen peroxide is:
Correct Answer: B
Rationale: The correct answer is B: Catalase. Catalase is the enzyme responsible for breaking down hydrogen peroxide into water and oxygen. This process helps protect the bacteria from oxidative damage caused by hydrogen peroxide. Amylase (A), Lipase (C), and Protease (D) are enzymes that are not involved in breaking down hydrogen peroxide. Amylase is involved in breaking down starch, Lipase breaks down lipids, and Protease breaks down proteins. Therefore, they are not the correct enzymes for the given question.
Question 2 of 9
The organisms to be identified have a nucleus surrounded by a nuclear membrane. Genetic material is concentrated predominantly in the chromosomes which consist of DNA strands and protein molecules. These cells divide mitotically. Identify these organisms:
Correct Answer: A
Rationale: Step-by-step rationale: 1. The presence of a nucleus with a nuclear membrane indicates eukaryotic cells. 2. Eukaryotes have genetic material in chromosomes made of DNA and proteins. 3. Mitotic division is characteristic of eukaryotic cells. 4. Therefore, the organisms described are eukaryotes. Summary: - Bacteriophages (B) are viruses that infect bacteria. - Prokaryotes (C) lack a nucleus and their genetic material is not organized into chromosomes. - Viruses (D) are not considered living organisms and do not have a nucleus or chromosomes.
Question 3 of 9
A patient consulted a doctor about bowels disfunction. The doctor established symptoms of duodenitis and enteritis. Laboratory examination helped to make the following diagnosis: lambliosis. What medication should be administered?
Correct Answer: A
Rationale: Rationale: Metronidazole is the drug of choice for treating lambliosis due to its effectiveness against Giardia lamblia, the parasite causing the infection. Metronidazole works by disrupting the DNA structure of the parasite, leading to its death. Erythromycin (choice B) is not effective against Giardia lamblia. Monomycin (choice C) and Chingamin (choice D) are not commonly used for treating lambliosis. Therefore, choice A, Metronidazole, is the correct medication for this patient.
Question 4 of 9
What is the function of bacterial pili?
Correct Answer: B
Rationale: The function of bacterial pili is to aid in adhesion. Pili are hair-like structures on the bacterial surface that help the bacteria attach to surfaces or other cells. This adhesion is crucial for colonization and infection. Pili do not provide motility, as that is typically done by flagella. Bacteria form spores for survival under harsh conditions, and protein synthesis is carried out by ribosomes, not pili. Thus, the correct answer is B, aiding in adhesion.
Question 5 of 9
The enzyme used by bacteria to break down hydrogen peroxide is:
Correct Answer: B
Rationale: The correct answer is B: Catalase. Catalase is the enzyme responsible for breaking down hydrogen peroxide into water and oxygen. This process helps protect the bacteria from oxidative damage caused by hydrogen peroxide. Amylase (A), Lipase (C), and Protease (D) are enzymes that are not involved in breaking down hydrogen peroxide. Amylase is involved in breaking down starch, Lipase breaks down lipids, and Protease breaks down proteins. Therefore, they are not the correct enzymes for the given question.
Question 6 of 9
The bacteria that produces a thick pseudomembrane in the throat is:
Correct Answer: A
Rationale: Rationale: 1. Corynebacterium diphtheriae is the correct answer as it is the bacteria responsible for causing diphtheria, characterized by a thick pseudomembrane in the throat. 2. Streptococcus pyogenes causes strep throat but does not produce a pseudomembrane. 3. Neisseria meningitidis causes meningitis and septicemia, not a throat pseudomembrane. 4. Bacillus cereus causes food poisoning, not throat-related symptoms.
Question 7 of 9
After the transfer of the F plasmid from the donor to the recipient cell..
Correct Answer: D
Rationale: After the transfer of the F plasmid from the donor to the recipient cell, the correct answer is D. This is because the F plasmid carries genes for conjugation, allowing the recipient cell to become F+ (containing the F plasmid). The donor cell remains F. Choice A is incorrect as the outcome can be predicted based on the transfer of the F plasmid. Choice B is incorrect because the donor cell does not become F after transferring the F plasmid. Choice C is incorrect as only the recipient cell becomes F+, not both cells.
Question 8 of 9
What type of bacteria is responsible for the formation of acid in the stomach?
Correct Answer: B
Rationale: The correct answer is B: Helicobacter pylori. This bacterium is responsible for stomach acid formation by producing an enzyme called urease, which converts urea into ammonia and carbon dioxide, leading to an increase in stomach pH. Staphylococcus aureus (A) does not cause stomach acid formation. Bacillus cereus (C) and Clostridium botulinum (D) are not involved in stomach acid processes.
Question 9 of 9
Which of the following bacteria produces an endotoxin responsible for septic shock?
Correct Answer: D
Rationale: The correct answer is D, "All of the above." Staphylococcus aureus, Escherichia coli, and Neisseria meningitidis all produce endotoxins that can lead to septic shock. Endotoxins are part of the outer membrane of Gram-negative bacteria, such as E. coli and N. meningitidis, which can trigger a severe immune response leading to septic shock. S. aureus, a Gram-positive bacterium, produces toxins that can also contribute to septic shock. Therefore, all of these bacteria can produce endotoxins responsible for septic shock. Choices A, B, and C are incorrect because they only identify individual bacteria that produce endotoxins, whereas the correct answer encompasses all bacteria listed.