Nokea
Production of auto-antibodies may be due to:
- A. Emergence of mutant clones of B cells
- B. Production of antibodies against hidden tissues
- C. Genetic factors
- D. All of these
Correct Answer: D
Rationale: Production of auto-antibodies can be due to various factors. Mutant B cell clones can lead to the production of self-reactive antibodies. Antibodies against hidden tissues can also trigger autoimmune responses. Genetic factors play a crucial role in predisposing individuals to autoimmunity. Therefore, the correct answer is D, as all these factors can contribute to the production of auto-antibodies. Choice A is incorrect as it only addresses one possible cause. Choice B is incorrect as it focuses solely on antibodies against hidden tissues. Choice C is incorrect as it overlooks the other potential reasons for auto-antibody production.
You may also like to solve these questions
Microscopy of a wound abscess revealed Gram-negative rods producing blue-green pigment with a distinctive odor of jasmine. What is the likely causative agent?
- A. Pseudomonas aeruginosa
- B. Proteus vulgaris
- C. Escherichia coli
- D. Klebsiella pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known for producing a blue-green pigment called pyocyanin, which gives the characteristic color seen in the wound abscess. The distinctive odor of jasmine is also a key feature of Pseudomonas aeruginosa. Proteus vulgaris (B) and Klebsiella pneumoniae (D) do not produce blue-green pigment or have a jasmine-like odor. Escherichia coli (C) typically does not produce blue-green pigment or have a jasmine-like odor.
Which bacteria is responsible for causing tuberculosis?
- A. Mycobacterium tuberculosis
- B. Streptococcus pneumoniae
- C. Salmonella enterica
- D. Neisseria meningitidis
Correct Answer: A
Rationale: The correct answer is A: Mycobacterium tuberculosis. This bacterium is responsible for causing tuberculosis. It is a slow-growing, acid-fast bacillus that primarily affects the lungs. Mycobacterium tuberculosis is transmitted through the air via respiratory droplets. Choice B, Streptococcus pneumoniae, is a common cause of pneumonia but not tuberculosis. Choice C, Salmonella enterica, causes food poisoning. Choice D, Neisseria meningitidis, causes meningitis, not tuberculosis. Therefore, Mycobacterium tuberculosis is the correct answer based on its characteristics and mode of transmission.
A 34-year-old male visited Tajikistan. After return, he complains of fever up to 40oC which occurs every second day and is accompanied by chills, sweating. Hepatosplenomegaly is present. Blood test results: RBC- 3x1012/l, b- 80 g/l, WBC- 4x109/l, eosinophils - 1%, stab neutrophils - 5%, segmented neutrophils - 60%, lymphocytes - 24%, monocytes - 10%, ESR - 25 mm/h. What is the provisional diagnosis?
- A. Malaria
- B. Infectious mononucleosis
- C. Sepsis
- D. Typhoid fever
Correct Answer: A
Rationale: The correct answer is A: Malaria. The patient's travel history to an endemic area like Tajikistan, along with symptoms of fever with chills, sweating, and hepatosplenomegaly, are classic for malaria. The blood test results show anemia (low RBC and hemoglobin levels), which can occur in malaria due to hemolysis. The presence of eosinophils and lymphocytes are not typical for malaria, but the overall clinical picture fits. Infectious mononucleosis (choice B) typically presents with sore throat, lymphadenopathy, and atypical lymphocytosis, which are not seen in this case. Sepsis (choice C) is characterized by systemic inflammatory response syndrome and organ dysfunction due to infection, which does not align with the symptoms and findings in the case. Typhoid fever (choice D) usually presents with gradual onset of sustained fever, abdominal pain, headache, and constipation, which are not present in this patient
Bypass fume hoods belong to the group of
- A. general-purpose hoods.
- B. radioisotope hoods.
- C. perchloric acid hoods.
- D. biosafety cabinets.
Correct Answer: A
Rationale: The correct answer is A: general-purpose hoods. Bypass fume hoods are designed to handle a wide range of chemical fumes and vapors, making them suitable for various types of experiments and processes. They are not specifically designed for radioisotopes (B), perchloric acid (C), or biological materials (D). Therefore, A is the correct choice for bypass fume hoods.
Which of the following bacteria is responsible for causing tuberculosis?
- A. Mycobacterium leprae
- B. Mycobacterium tuberculosis
- C. Streptococcus pneumoniae
- D. Neisseria gonorrhoeae
Correct Answer: B
Rationale: The correct answer is B: Mycobacterium tuberculosis. This bacterium is responsible for causing tuberculosis. Mycobacterium leprae (choice A) causes leprosy, not tuberculosis. Streptococcus pneumoniae (choice C) is known for causing pneumonia, not tuberculosis. Neisseria gonorrhoeae (choice D) is responsible for causing gonorrhea, not tuberculosis. Mycobacterium tuberculosis is the specific bacterium associated with tuberculosis due to its ability to infect the lungs and other organs, leading to the characteristic symptoms of the disease.