microbiology chapter 12 test bank

Correct Answer: D

Rationale: The correct answer is D because Cytomegalovirus infections are caused by human herpesvirus 5, also known as Human Herpesvirus 5 (HHV-5) or Cytomegalovirus (CMV). This virus belongs to the Herpesviridae family, genus Betaherpesvirinae. Options A, B, and C are incorrect as they do not correspond to the specific virus responsible for causing Cytomegalovirus infections.

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.

Correct Answer: C

Rationale: The correct answer is C: Inhibits protein synthesis. Exotoxin of C. Diphtheriae acts by inhibiting protein synthesis in host cells. This disrupts cellular functions and leads to tissue damage. Choice A is incorrect because acetylcholine release is not affected. Choice B is incorrect as it does not involve neurotransmitters. Choice D is incorrect as the exotoxin does have a specific mechanism.

Correct Answer: D

Rationale: The correct answer is D: Multiplies by binary fission. Bacterial cells reproduce through binary fission, where a single cell divides into two identical daughter cells. This process is essential for bacterial growth and multiplication. A: The oxidative phosphorylation does not take place in the mitochondria of bacterial cells but in the cell membrane. B: Capsules are not organelles but outer protective layers found in some bacterial cells. C: Bacterial cells contain both DNA and RNA, essential for their genetic information and protein synthesis.

Correct Answer: C

Rationale: The correct answer is C. Negri bodies are not associated with measles but with rabies. Step 1: Measles is a childhood infection with a rash (A). Step 2: Koplik spots are small white spots on a red base found inside the mouth and are characteristic of measles (B). Step 3: Negri bodies are eosinophilic cytoplasmic inclusions found in neurons infected with rabies virus, not measles (C). Step 4: Prophylaxis for measles is through the MMR vaccine, which is a live attenuated vaccine (D). Therefore, choice C is incorrect as it does not pertain to measles.