Which scientist performed the first successful vaccination against smallpox?
- A. Pasteur
- B. Jenner
- C. Semmelweis
- D. Koch
Correct Answer: B
Rationale: The correct answer is B: Jenner. Edward Jenner is credited with performing the first successful vaccination against smallpox in 1796. He used cowpox virus to inoculate individuals, leading to immunity against smallpox. Jenner's experiment laid the foundation for modern vaccination. Pasteur (A) is known for developing the germ theory of disease. Semmelweis (C) advocated for handwashing to prevent infections. Koch (D) identified the causative agents of several diseases but did not develop the smallpox vaccine.
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Which of the following stains is the most widely used differential stain in hematology laboratories?
- A. Carbolfuchsin stain
- B. Wright’s stain
- C. Ziehl-Neelson stain
- D. Kinyoun stain
Correct Answer: D
Rationale: The correct answer is D: Kinyoun stain. This stain is the most widely used differential stain in hematology labs because it is specifically designed for acid-fast bacteria like Mycobacterium tuberculosis. It differentiates these bacteria from others based on their cell wall composition. Carbolfuchsin stain (A) is used for acid-fast bacteria in microbiology. Wright's stain (B) is used for blood cell morphology. Ziehl-Neelsen stain (C) is also used for acid-fast bacteria but is less commonly used compared to Kinyoun stain in hematology labs.
In humans, the embryonic phase of development extends from fertilization to the end of week __________, after which the developing infant is called a fetus.
- A. 2
- B. 6
- C. 8
- D. 12
Correct Answer: C
Rationale: The correct answer is C: 8. The embryonic phase in humans lasts until the end of week 8. During this time, the major organs and structures of the body begin to form. After week 8, the developing organism is referred to as a fetus. Choice A (2) is too early for this transition to occur, Choice B (6) is also premature, and Choice D (12) is too late as the embryonic phase ends before week 12. Therefore, the correct answer is C (8) as it accurately reflects the timeline of embryonic development in humans.
Poxviruses are DNA viruses that replicate in the cytoplasm.
- A. TRUE
- B. FALSE
- C. Partially
- D. Not Sure
Correct Answer: A
Rationale: Step 1: Poxviruses are indeed DNA viruses, confirmed by scientific research.
Step 2: Poxviruses replicate entirely in the cytoplasm, unlike most DNA viruses.
Step 3: Cytoplasmic replication is a unique characteristic of poxviruses.
Step 4: The replication process of poxviruses in the cytoplasm is well-documented.
Step 5: Therefore, option A (TRUE) is correct, as poxviruses replicate in the cytoplasm exclusively.
Patients planned for treatment with monoclonal antibodies are tested for:
- A. HBV
- B. HCV
- C. M. tuberculosis
- D. All are correct
Correct Answer: D
Rationale: The correct answer is D: All are correct. Patients planned for treatment with monoclonal antibodies should be tested for HBV, HCV, and M. tuberculosis due to the risk of reactivation of these infections during treatment. HBV and HCV reactivation can lead to severe liver damage, while M. tuberculosis reactivation can cause serious respiratory complications. Testing for all three infections helps in identifying and managing any pre-existing infections to ensure patient safety during monoclonal antibody treatment. Choices A, B, and C are incorrect because each of these infections presents specific risks that need to be assessed before initiating monoclonal antibody therapy.
Which bacteria is commonly associated with foodborne illnesses?
- A. Streptococcus pneumoniae
- B. Campylobacter jejuni
- C. Mycobacterium tuberculosis
- D. Haemophilus influenzae
Correct Answer: B
Rationale: The correct answer is B: Campylobacter jejuni. This bacteria is commonly associated with foodborne illnesses due to its presence in undercooked poultry and unpasteurized milk. Campylobacteriosis is a leading cause of bacterial gastroenteritis. Streptococcus pneumoniae (A) causes pneumonia, not foodborne illnesses. Mycobacterium tuberculosis (C) causes tuberculosis, not foodborne illnesses. Haemophilus influenzae (D) can cause respiratory infections but is not commonly associated with foodborne illnesses.