Which of the following bacteria is associated with the disease tuberculosis?

Correct Answer: B

Rationale: Step 1: Mycobacterium tuberculosis is a bacterium known to cause tuberculosis. Step 2: Mycobacterium leprae causes leprosy, not tuberculosis. Step 3: Streptococcus pneumoniae causes pneumonia, not tuberculosis. Step 4: Neisseria gonorrhoeae causes gonorrhea, not tuberculosis. Conclusion: Mycobacterium tuberculosis is the correct answer as it is the only bacterium associated with tuberculosis among the choices provided.

Correct Answer: B

Rationale: The correct answer is B: 1971. OSHA, the Occupational Safety and Health Administration, was established in 1971 under the Occupational Safety and Health Act signed by President Richard Nixon. This act aimed to ensure safe and healthy working conditions for employees by setting and enforcing standards. Choices A, C, and D are incorrect as OSHA was not established in those years. Option A (1921) is too early, option C (1980) is after OSHA was already established, and option D (1985) is also too late. Therefore, the correct answer is B, 1971, as it aligns with the historical establishment of OSHA.

Correct Answer: C

Rationale: The correct answer is C: Proteus mirabilis. This bacterium shows swarming on blood agar due to its ability to produce flagella and exhibit rapid and coordinated movement. Providencia stuartii and Providencia rettgeri are not known for swarming behavior on blood agar. Morganella morganii can exhibit swarming motility, but it is not as commonly associated with this characteristic compared to Proteus mirabilis, making C the most appropriate choice.

Correct Answer: C

Rationale: The correct answer is C because F pili are proteins on the F+ donor cell that are attached to specific receptors on the recipient cell's cell wall. This is essential for the transfer of genetic material during conjugation. Choice A is incorrect because F pili are not made up of nucleotides, but rather proteins. Choice B is incorrect because F pili are not transferred to the recipient cell itself, but they facilitate the transfer of genetic material. Choice D is incorrect because F pili are not part of the recipient cell, but rather part of the donor cell for attachment to the recipient cell.

Correct Answer: A

Rationale: Rationale: 1. Metronidazole is known to inhibit aldehyde dehydrogenase, an enzyme involved in alcohol metabolism. 2. Inhibition of this enzyme leads to accumulation of acetaldehyde, causing unpleasant symptoms when alcohol is consumed. 3. This reaction is known as the disulfiram-like reaction. 4. Reserpine, Clonidine, and Diazepam do not have this specific mechanism of action. Summary: - Option A (Metronidazole) is correct due to its inhibition of alcohol metabolism. - Options B, C, and D are incorrect as they do not exhibit this interaction with alcohol metabolism.

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: C

Rationale: Disinfection is the process of destroying the vegetative forms of microorganisms, but their spores may survive. This is why choice C is correct. The other choices are incorrect because: A: Disinfection does not necessarily target spore forms exclusively. B: While disinfection targets vegetative forms, it does not always eliminate spore forms. D: Disinfection is not primarily used for determining the effect of physical agents on microorganisms.

Correct Answer: A

Rationale: Step-by-step rationale for the correct answer (A: Epstein-Barr virus): 1. Epstein-Barr virus is a member of the Herpesviridae family, known for causing infectious mononucleosis. 2. Members of Herpesviridae have double-stranded DNA genomes and enveloped virions. 3. They establish latent infections in host cells and can reactivate periodically. 4. Poxvirus (B) belongs to the Poxviridae family, not Herpesviridae. 5. SARS (C) is caused by a coronavirus, not a herpesvirus. 6. HIV (D) belongs to the Retroviridae family, not Herpesviridae. Summary: The correct answer is A because Epstein-Barr virus is a member of the Herpesviridae family, exhibiting specific characteristics distinct from the other choices.

Correct Answer: A

Rationale: Rationale: The correct answer is A: Syphilis. Spiral microorganisms with pointed ends are characteristic of Treponema pallidum, the causative agent of syphilis. This bacterium is known for its corkscrew shape. Other choices are incorrect because Leptospirosis, Lyme disease, and Relapsing fever are caused by different pathogens and do not exhibit spiral microorganisms on blood smears. Syphilis should be suspected in the presence of these specific spiral microorganisms.