free microbiology test bank questions pdf

Correct Answer: D

Rationale: The correct answer is D because polio viruses are primarily found in the gastrointestinal tract and respiratory secretions. Feces contain the highest concentration of the virus, while nasopharyngeal swabs and cerebrospinal fluid can also contain the virus. Blood, sputum, and urine do not typically contain high levels of polio virus. Choice A is incorrect as bile content is not a common site for polio virus isolation. Choice C is incorrect because only testing feces may not provide a comprehensive picture of the infection.

Correct Answer: C

Rationale: The correct answer is C: Bacillus anthracoides. 1. The patient's symptoms align with cutaneous anthrax, caused by Bacillus anthracis. 2. Presence of immobile streptobacilli able of capsulation matches the characteristics of Bacillus anthracis. 3. Symptoms such as black crust, peripheral vesicular rash, and non-painful edema are classic for cutaneous anthrax. 4. Choice A: Bacillus antracis is a misspelling, not a valid option. 5. Choice B: Staphylococcus aureus does not match the symptoms described in the scenario. 6. Choice D: Bacillus megaterium is not associated with cutaneous anthrax.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Clostridium botulinum produces botulinum toxin causing botulism. Salmonella enterica can produce enterotoxins causing food poisoning. Staphylococcus aureus also produces enterotoxins leading to food poisoning. Therefore, all three options can cause food poisoning due to their production of enterotoxins.

Correct Answer: C

Rationale: The correct answer is C because nucleoids in bacteria can vary in number from 1 to 4 depending on the specific bacterial cell and its growth and replication phases. This is due to the dynamic nature of bacterial cells and their genetic material organization. Choice A is incorrect because nucleoids do not contain nuclear membranes or multiple haploid chromosomes like eukaryotic nuclei. Choice B is incorrect as there is no known method of reabsorbing nucleoids by Neisser. Choice D is incorrect as option C is indeed the correct statement regarding the number of nucleoids in bacterial cells.

Correct Answer: A

Rationale: The correct answer is A because fires from combustibles such as wood fall under Class A fires. Type A fire extinguishers are specifically designed to extinguish fires involving ordinary combustible materials like wood, paper, and cloth. Choice B, C, and D are incorrect because they do not correspond to the correct classification of the fire. Choice B refers to Class B fires involving flammable liquids, Choice C refers to Class C fires involving electrical equipment, and Choice D refers to Class D fires involving combustible metals. It is crucial to match the type of fire extinguisher with the type of fire to effectively combat the fire.