ATI RN
microbiology chapter 12 test bank Questions
Question 1 of 5
Which of the following statements regarding S. aureus is not true:
Correct Answer: C
Rationale: Step 1: S. aureus is known to produce hemolysins, leucocidins, and enterotoxin. Step 2: S. aureus colonies usually exhibit golden-yellow pigmentation with beta-hemolytic zones. Step 3: S. aureus has developed resistance to penicillin due to the production of beta-lactamase. Step 4: Therefore, statement C is not true as S. aureus is not always sensitive to penicillin. Summary: Choices A and B are correct statements about S. aureus, while choice C is incorrect due to the increasing penicillin resistance seen in S. aureus.
Question 2 of 5
Which of the following organelles contain oxidative enzymes capable of oxidizing toxic substances?
Correct Answer: D
Rationale: The correct answer is D: peroxisomes. Peroxisomes contain oxidative enzymes, such as catalase and peroxidase, that are capable of oxidizing toxic substances. These enzymes help detoxify harmful molecules by breaking them down into harmless products. Lysosomes (choices B and C) contain hydrolytic enzymes for breaking down cellular waste, not oxidative enzymes. Therefore, the correct choice is peroxisomes due to their specific function in detoxification through oxidation reactions.
Question 3 of 5
The antibiotics penicillin and cephalosporin are produced by:
Correct Answer: C
Rationale: The correct answer is C: fungi. Both penicillin and cephalosporin are produced by certain species of fungi. Penicillin is derived from the Penicillium fungi, while cephalosporin is produced by Cephalosporium fungi. Fungi have the ability to synthesize these antibiotics as part of their defense mechanisms against other microorganisms. Algae (A), slime molds (B), and protozoans (D) do not have the capability to produce antibiotics like penicillin and cephalosporin. Algae are mainly photosynthetic organisms, slime molds are protists that lack the ability to synthesize complex antibiotics, and protozoans are single-celled eukaryotic organisms that do not produce antibiotics like fungi do.
Question 4 of 5
Media that contain complex organic substances such as blood for the growth of specific bacteria are referred to as:
Correct Answer: A
Rationale: The correct answer is A: enriched media. Enriched media contain additional nutrients such as blood to support the growth of fastidious bacteria. This allows for the cultivation of a wider range of microorganisms. General-purpose media (B) contain basic nutrients for a variety of bacteria. Reducing media (C) create anaerobic conditions, not necessarily rich in organic substances. Differential media (D) contain indicators to distinguish between different types of microorganisms, not necessarily enriched with organic substances.
Question 5 of 5
The term used to indicate the extent to which a drug reaches its site of action is:
Correct Answer: B
Rationale: The correct answer is B: bioavailability. Bioavailability refers to the extent and rate at which a drug reaches its site of action in the body. This includes factors such as absorption, distribution, metabolism, and excretion. Rationale: 1. Bioactivity refers to the pharmacological effect of a drug, not how effectively it reaches its site of action. 2. Bioremediation is the process of using organisms to remove or neutralize pollutants, not related to drug delivery. 3. Biostasis refers to a state of equilibrium or balance in living organisms, not related to drug transport to its site of action. In summary, bioavailability is the most appropriate term as it specifically addresses the process of a drug reaching its intended target within the body, distinguishing it from the other choices.