microbiology chapter 11 test bank

Correct Answer: D

Rationale: The correct answer is D: Cell cultures. Rotavirus diagnosis involves detecting viral antigens in stool samples using cell cultures. Cell cultures allow for the replication of the virus, facilitating its identification. A: Egg inoculation and B: Sensitive laboratory animals are not commonly used for Rotavirus diagnosis due to ethical concerns and practical limitations. C: Ascoli test is used for detecting specific proteins in serum, not for Rotavirus detection in stool samples. In summary, cell cultures are the most appropriate method for laboratory diagnosis of Rotavirus infection due to their ability to support viral replication and antigen detection.

Correct Answer: D

Rationale: Rationale: 1. Rickettsiae are obligate intracellular bacteria, hence they do not form spores, capsules, or flagella. 2. They have a slim glycocalyx layer, aiding in attachment to host cells. 3. Bipolar fimbriae are structures that help in adhesion to host cells. Therefore, all statements (A, B, and C) are true for Rickettsiae, making option D the correct answer. Other choices are incorrect as they do not accurately describe the characteristics of Rickettsiae.

Correct Answer: B

Rationale: The correct answer is B: Candida albicans. Candida albicans is the most common cause of vaginal yeast infections due to its ability to overgrow in warm, moist environments like the vagina. It is a type of fungus that naturally resides in the body, but can cause infection when its growth is not regulated. Histoplasma capsulatum (A) causes a lung infection, Aspergillus niger (C) causes fungal sinusitis, and Saccharomyces cerevisiae (D) is a type of yeast used in baking and brewing, not typically associated with vaginal infections.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Mumps is a contagious disease transmitted through air droplets and direct contact. 2. The correct answer is A because mumps can infect both humans and animals. 3. Choice B is incorrect as mumps is vaccine-preventable. 4. Choice C is correct as mumps is highly contagious. 5. Choice D is accurate as mumps is transmitted via air droplets and direct contact. Summary: The correct answer is A because mumps can infect both humans and animals, making it untrue that only humans can be infected. Choices B, C, and D are incorrect as mumps is vaccine-preventable, highly contagious, and transmitted through air droplets and direct contact.

Correct Answer: C

Rationale: The correct answer is C: Lag phase. During the lag phase, bacteria adapt to the new environment before starting to grow and divide. This phase is characterized by a period of low growth as bacteria adjust their metabolism to the available nutrients. The stationary phase (A) is when growth rate equals death rate, the log phase (B) is rapid exponential growth, and the death phase (D) is when cells start to die due to nutrient depletion or accumulation of waste products. Thus, the lag phase is the initial phase where bacteria prepare for growth, making it the correct answer.