microbiology an introduction tortora test bank

Correct Answer: C

Rationale: The correct answer is C: Replication. In DNA replication, the original DNA molecule is unwound and each strand serves as a template to synthesize a new complementary strand. This results in two identical copies of the original DNA molecule. Translation (A) is the process of synthesizing proteins from mRNA. Transcription (B) is the process of synthesizing mRNA from DNA. Cell division (D) is the process of a cell dividing into two daughter cells, not specifically producing identical DNA copies. Therefore, replication is the correct answer as it specifically refers to the process of copying DNA to produce two identical copies.

Correct Answer: A

Rationale: The correct answer is A: Blue pus bacillus. Pseudomonas genus includes bacteria that commonly cause diseases in plants. Blue pus bacillus is a common name for Pseudomonas aeruginosa, a well-known bacterium that causes diseases in medicinal plants. Explanation: 1. Blue pus bacillus (Pseudomonas aeruginosa) is a member of the Pseudomonas genus known for causing diseases in plants. 2. Colon bacillus (Escherichia coli) belongs to the Enterobacteriaceae family, not the Pseudomonas genus. 3. Proteus is a genus of the Enterobacteriaceae family, not Pseudomonas. 4. Mycoplasma is a genus of bacteria that lack a cell wall and are not related to the Pseudomonas genus. In summary, the correct answer is A because it is a member of the Pseudomonas genus known for causing diseases in medicinal plants, while

Correct Answer: C

Rationale: The correct answer is C: Intracellular parasitism. Genus Rickettsia representatives are known for their ability to live and replicate inside the host's cells, making them obligate intracellular parasites. This characteristic distinguishes them from other bacteria. A: Gram-positive cell wall is incorrect because Rickettsia have a gram-negative cell wall. B: High resistance to external environment factors is incorrect because Rickettsia are sensitive to environmental conditions and require specific host cells for survival. D: None of the above is incorrect because Rickettsia do exhibit the characteristic of intracellular parasitism.

Correct Answer: A

Rationale: The correct answer is A: Vibrio cholerae. This bacterium produces cholera toxin, an exotoxin that causes severe dehydration and diarrhea by increasing the secretion of electrolytes and water in the intestines. Vibrio cholerae is the causative agent of cholera, a disease characterized by profuse watery diarrhea. Choice B, Clostridium tetani, produces tetanospasmin causing tetanus, not dehydration or diarrhea. Choice C, Escherichia coli, can cause diarrhea but rarely severe dehydration. Choice D, Shigella dysenteriae, produces Shiga toxin leading to bloody diarrhea, not severe dehydration.

Correct Answer: B

Rationale: The correct answer is B because the complement fixation test is a serological test that detects the presence of specific antibodies or antigens in a patient's serum. It works by measuring the ability of antibodies to fix complement proteins. Choice A is incorrect because the complement fixation test typically involves several steps, not necessarily three. Choice C is incorrect as standardized complement proteins are commonly used in this test. Choice D is incorrect because sheep red blood cells are not essential for performing the complement fixation test.