Microbiology Chapter 1 Test Bank

Correct Answer: A

Rationale: The Burri-Gins staining technique is used to identify capsule formation in bacteria. Capsules are protective layers around bacteria that can be visualized using this staining method. Capsules are important virulence factors for pathogens like Yersinia pestis, the causative agent of plague. This technique helps in differentiating encapsulated bacteria from non-encapsulated ones. Spore formation (B), acid resistance (C), and alkali resistance (D) are not properties that can be identified using the Burri-Gins technique, making them incorrect choices.

Correct Answer: C

Rationale: The correct answer is C. Prostatitis is inflammation of the prostate gland, leading to symptoms like painful urination, fever/chills, and weak urine flow. Painful urination is due to irritation of the urinary tract by the inflamed prostate. Fever/chills indicate an infection, common in prostatitis. Weak urine flow is due to obstruction caused by the inflamed prostate. Choice A is incorrect as muscle aches, sore throat, and swollen lymph nodes are not typical symptoms of prostatitis. Choice B is incorrect as painful joints and nausea are not characteristic symptoms. Choice D is almost identical to the correct answer but includes an extra symptom of painful joints, which is not associated with prostatitis.

Correct Answer: B

Rationale: The correct answer is B: Cholera. Cholera is caused by Gram-negative curved rod-like bacteria called Vibrio cholerae, commonly found in contaminated water or food. The characteristic symptom of cholera is profuse watery diarrhea, which matches the patient's presentation. Typhoid fever (A) is caused by Salmonella typhi, which is not a curved rod-like bacteria. Diphtheria (C) is caused by Corynebacterium diphtheriae, a Gram-positive bacterium, and does not typically cause diarrhea. Intestinal form of plague (D) is caused by Yersinia pestis, which is not a curved rod-like bacteria and does not typically present with diarrhea.

Correct Answer: C

Rationale: The correct answer is C: Thick peptidoglycan layer. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet stain in the Gram staining process, leading to a purple color. This thick layer is a defining characteristic of Gram-positive bacteria. Rationale: A: Thin peptidoglycan layer is incorrect because Gram-positive bacteria have a thick peptidoglycan layer. B: Presence of an outer membrane is incorrect because Gram-positive bacteria lack an outer membrane. D: Presence of lipopolysaccharides is incorrect because lipopolysaccharides are typically found in the outer membrane of Gram-negative bacteria, not Gram-positive bacteria.

Correct Answer: D

Rationale: The correct answer is D: active transport system. Permeases are specific carriers that actively transport molecules across a cell membrane against their concentration gradient, requiring energy input. This process is known as active transport, which is essential for maintaining cellular homeostasis and allowing the cell to accumulate specific molecules. Facilitated diffusion (A) and passive transport (B) both involve the movement of molecules down their concentration gradient without the need for energy input. Simple diffusion (C) also does not involve specific carriers and relies on the natural movement of molecules from areas of high concentration to low concentration. Therefore, the correct choice is D as permeases specifically function in active transport systems.