Microbiology Chapter 10 Test Bank

Correct Answer: A

Rationale: The correct answer is A: Neutralization reaction. This is the most appropriate serological test to reveal botulinum toxin because it involves mixing the patient's serum with known botulinum antitoxin. If the patient's serum contains botulinum toxin, it will neutralize the antitoxin, leading to a lack of toxin-neutralizing ability. The other choices are incorrect because agglutination reaction involves clumping of cells, not suitable for detecting botulinum toxin; Bordet-Gengou test is used to detect antibodies in pertussis infection, not botulinum toxin; and precipitation reaction involves the formation of a solid when two solutions are mixed, not ideal for detecting botulinum toxin.

Correct Answer: B

Rationale: The correct answer is B: ribosome. Ribosomes are responsible for protein synthesis, not packaging. The Golgi complex (A) processes and packages proteins. The rough endoplasmic reticulum (rER) (C) is involved in protein synthesis and transport. Lysosomes (D) contain enzymes for digestion, not protein packaging. Therefore, ribosomes are the organelle directly involved in protein synthesis, making it the correct choice.

Correct Answer: D

Rationale: The correct answer is D: polyomavirus infections. Polyomavirus infections do not typically recur during pregnancy because once the virus infects the body, it remains latent without causing recurrent infections. In contrast, choices A, B, and C can recur during pregnancy due to their ability to reactivate from latency or reinfect the host. Epstein-Barr virus infections (choice A) can lead to infectious mononucleosis, herpes simplex virus infections (choice B) can cause recurrent genital or oral herpes outbreaks, and streptococcal infections (choice C) can result in recurrent throat or skin infections.

Correct Answer: B

Rationale: The correct answer is B: Shagreen leather. Yersinia pestis, the bacterium causing plague, forms colonies resembling shagreen leather on a hard nutrient medium due to its distinctive morphology. This morphology includes a rough, irregular, and raised appearance, similar to the texture of shagreen leather. A: Dewdrops - Incorrect. Dewdrops do not accurately describe the colony morphology of Yersinia pestis. C: Lace handkerchief - Incorrect. Lace handkerchief does not accurately describe the colony morphology of Yersinia pestis. D: Mercury drops - Incorrect. Mercury drops do not accurately describe the colony morphology of Yersinia pestis.

Correct Answer: A

Rationale: The correct answer is A: tRNA. Anticodons are sequences of nucleotides found on tRNA molecules that complement the codons on mRNA during translation. tRNA molecules carry specific amino acids to the ribosome based on the codon-anticodon pairing. Option B, rRNA, forms the structure of the ribosome and is not directly involved in anticodon recognition. Option C, mRNA, contains codons but not anticodons. Option D, ribosomes, are the site of protein synthesis but do not contain the anticodons themselves.