Nokea
In the sixteenth century a father-and-son team, by the name of __________, produced a compound microscope consisting of a simple tube with lenses at each end.
- A. van Leeuwenhoek
- B. Semmelweis
- C. Janssen
- D. Hooke
Correct Answer: C
Rationale: The correct answer is C: Janssen. In the 16th century, Zacharias Janssen and his father Hans Janssen are credited with inventing the compound microscope. They constructed a simple tube with lenses at each end, allowing for magnification of small objects. This innovation laid the foundation for the development of modern microscopes. Van Leeuwenhoek is known for his contributions to microbiology but did not invent the compound microscope. Semmelweis is known for his work in handwashing and preventing infections. Hooke made significant contributions to microscopy but did not invent the compound microscope.
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Infectious mononucleosis most often occurs in:
- A. infants
- B. adolescents
- C. young adults
- D. the elderly
Correct Answer: B
Rationale: The correct answer is B: adolescents. Infectious mononucleosis is commonly caused by the Epstein-Barr virus, which is transmitted through saliva. Adolescents are more likely to engage in activities like kissing and sharing drinks, increasing the chances of virus transmission. Infants have maternal antibodies for protection, young adults may have developed immunity, and the elderly have had more exposure to the virus and may have built immunity over time.
Which of the following bacteria is associated with the disease tuberculosis?
- A. Mycobacterium leprae
- B. Mycobacterium tuberculosis
- C. Streptococcus pneumoniae
- D. Neisseria gonorrhoeae
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.
The degree or extent of disease-evoking power that a microorganism has is referred to as:
- A. virulence
- B. strength
- C. resistance
- D. competence
Correct Answer: A
Rationale: The correct answer is A: virulence. Virulence refers to the degree or extent of disease-evoking power that a microorganism possesses. This term specifically describes the ability of a microorganism to cause disease in a host. It is a crucial factor in understanding the pathogenicity of different microorganisms.
Choice B: strength is incorrect because it does not specifically relate to the disease-causing potential of a microorganism. Choice C: resistance refers to the ability of an organism to withstand the effects of a particular agent, such as a drug or environmental factor. Choice D: competence is not directly related to the disease-causing ability of a microorganism, but rather refers to the ability of an organism to perform a specific function effectively.
A patient presented with fever and cough. A sputum sample stained by Gram's method revealed Gram-positive diplococci with a capsule. What is the likely causative agent?
- A. Streptococcus pneumoniae
- B. Staphylococcus aureus
- C. Neisseria meningitidis
- D. Klebsiella pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. The presence of Gram-positive diplococci with a capsule is characteristic of S. pneumoniae. This bacterium is a common cause of pneumonia, especially in patients with fever and cough. It is also known for causing infections such as otitis media and sinusitis. Staphylococcus aureus (B) is a Gram-positive cocci but does not typically form diplococci or have a capsule. Neisseria meningitidis (C) is a Gram-negative diplococcus commonly associated with meningitis, not pneumonia. Klebsiella pneumoniae (D) is a Gram-negative rod, not a diplococcus, and is more commonly associated with pneumonia in immunocompromised patients.
A patient has got pain in the axillary area, rise of temperature developed 10 hours ago. On examination: shaky gait is evident, the tongue is coated with white deposit. The pulse is frequent. The painful lymphatic nodes are revealed in the axillary area. The skin over the lymph nodes is erythematous and glistering. What is the most probable diagnosis?
- A. Bubonic plague
- B. Acute purulent lymphadenitis
- C. Lymphogranulomatosis
- D. Anthrax
Correct Answer: B
Rationale: The correct answer is B: Acute purulent lymphadenitis. The symptoms described indicate an acute bacterial infection of the lymph nodes. The presence of painful lymph nodes, erythema, and shiny appearance of the skin overlying the nodes suggest an inflammatory process. The rise in temperature and frequent pulse indicate an active infection. The white-coated tongue may be a sign of systemic involvement. The shaky gait may indicate systemic toxicity. Bubonic plague (A) presents with buboes, not just painful lymph nodes. Lymphogranulomatosis (C) is a type of lymphoma and would not present with these acute bacterial infection symptoms. Anthrax (D) typically presents with a black eschar and is less likely in this context.