microbiology an introduction 12th edition test bank -Nurselytic

Correct Answer: C

Rationale: Sterilization refers to the complete elimination of all microorganisms, including their spores, which are the most resistant form of microbial life. Spores have a tough outer coating that protects them from harsh conditions, making them more difficult to destroy compared to vegetative cells, viruses, and protozoa.
Therefore, the correct answer is C because sterilization targets and eliminates all forms of microorganisms, including spores.

Choices A, B, and D are incorrect because sterilization goes beyond just targeting vegetative cells, viruses, or protozoa; it aims to eliminate all microorganisms present.

Correct Answer: B

Rationale: The correct answer is B: It causes epidemic meningitis. Neisseria Meningitidis is a bacterium that can cause meningitis, an infection of the protective membranes covering the brain and spinal cord. This bacterium is known to cause outbreaks or epidemics of meningitis, especially in crowded or close-contact settings. The other choices are incorrect because:
A: Neisseria Meningitidis does have a capsule, which helps it evade the immune system.
C: Neisseria Meningitidis grows on selective media like Thayer-Martin agar, not differential media.
D: Neisseria Meningitidis is a Gram-negative diplococcus, not a Gram-positive rod.

Correct Answer: B

Rationale: The correct answer is B: intravenous administration. This route bypasses the first-pass metabolism, allowing the drug to directly enter the bloodstream for immediate distribution. In contrast, on the skin (
A) and sublingual (
D) routes have slower absorption rates due to barriers like skin layers or mucous membranes. Intramuscular (
C) absorption is slower than intravenous due to slower perfusion rates in muscle tissues. Overall, intravenous administration provides the fastest and most direct route for drug absorption, making it the most rapid method.

Correct Answer: C

Rationale: The correct answer is C: Respiratory tract. The respiratory tract is likely the most frequently used portal of entry for pathogens because it is constantly exposed to the external environment and has a large surface area lined with mucous membranes that can trap and facilitate the entry of pathogens. Additionally, the respiratory tract serves as a direct pathway for pathogens to reach the bloodstream and other organs. Skin (choice
A) is a physical barrier that can prevent pathogen entry, while the gastrointestinal tract (choice
B) has acidic pH and enzymes that can kill many pathogens. Conjunctiva (choice
D) is a less common portal of entry compared to the respiratory tract due to its smaller surface area and protective mechanisms such as tears.

Correct Answer: A

Rationale: The correct answer is A: McConkey agar. Selective media selectively inhibit the growth of certain organisms while allowing others to grow. McConkey agar contains crystal violet and bile salts that inhibit the growth of Gram-positive bacteria, making it selective for Gram-negative bacteria.

Choices B and C are not selective media, as they do not specifically inhibit the growth of certain types of bacteria.
Choice D is incorrect as McConkey agar is indeed an example of selective media.