A child suspected for tuberculosis underwent Mantoux test. 24 hours after allergen injection there appeared a swelling, hyperaemia and tenderness. What are the main components in the development of this reaction?
- A. Mononuclears, T-lymphocytes and lymphokines
- B. Granulocytes, T-lymphocytes and IgG
- C. Plasmatic cells, T-lymphocytes and lymphokines
- D. B-lymphocytes, IgM
Correct Answer: A
Rationale: The correct answer is A: Mononuclears, T-lymphocytes and lymphokines. In a Mantoux test reaction, mononuclear cells, mainly T-lymphocytes, are activated by the injected allergen. These T-lymphocytes release lymphokines, leading to the observed swelling, hyperaemia, and tenderness. Granulocytes and IgG (choice B) are not the primary players in this type of delayed hypersensitivity reaction. Plasmatic cells (choice C) are not involved in the initial stages of this reaction. B-lymphocytes and IgM (choice D) are not the key components in the Mantoux test reaction.
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Fungi that help the roots of plants to absorb minerals and water from the soil are:
- A. decomposers
- B. mycorrhizae
- C. yeasts
- D. molds
Correct Answer: B
Rationale: The correct answer is B: mycorrhizae. Mycorrhizae are symbiotic fungi that form a mutualistic relationship with plant roots, aiding in the absorption of minerals and water. They enhance the plant's nutrient uptake capacity, promoting plant growth and health. Decomposers (A) break down dead organic matter, yeasts (C) are single-celled fungi used in fermentation, and molds (D) are fungi that grow in multicellular filaments. These options do not specifically assist plant roots in mineral and water absorption like mycorrhizae do.
A smear of a patient's sputum suspected for tuberculosis was prepared and stained. The smear showed red bacilli against a blue background. What staining method was used?
- A. Ziehl-Neelsen
- B. Gram
- C. Giemsa
- D. Neisser
Correct Answer: A
Rationale: The correct answer is A: Ziehl-Neelsen staining method. This method is used to detect acid-fast bacteria like Mycobacterium tuberculosis. Step-by-step rationale: 1. Acid-fast bacteria resist decolorization with acid-alcohol. 2. The red bacilli seen in the smear indicate acid-fast bacteria. 3. Ziehl-Neelsen stain uses carbol fuchsin to stain acid-fast bacteria red. 4. The blue background is likely the counterstain methylene blue. Incorrect choices: B: Gram stain is for categorizing bacteria into Gram-positive or Gram-negative, not specific for acid-fast bacteria. C: Giemsa stain is used for blood films and detecting parasites, not acid-fast bacteria. D: Neisser stain is not a standard microbiological staining method.
A bacteriological laboratory tests canned meat for botulinum toxin. Extract of the tested material and ABE botulinum antitoxin serum was introduced into the test group of mice; a control group of mice received the extract without antibotulinic serum. What serological reaction was used?
- A. Neutralization
- B. Precipitation
- C. Complement binding
- D. Double immunodiffusion
Correct Answer: A
Rationale: The correct answer is A: Neutralization. In this experiment, the ABE botulinum antitoxin serum is introduced along with the extract to neutralize the botulinum toxin. This is a specific type of serological reaction where the antitoxin serum binds to and neutralizes the toxin, preventing it from causing harm.
Summary:
- B: Precipitation involves the formation of visible insoluble complexes, which is not the case in this experiment.
- C: Complement binding involves the activation of complement proteins, which is not the main mechanism at play here.
- D: Double immunodiffusion is a technique to detect the presence of specific antigens or antibodies, but it is not directly related to the neutralization of toxins as seen in this experiment.
The binominal system of nomenclature was originally developed by
- A. Pasteur
- B. Linnaeus
- C. Martini
- D. Jenner
Correct Answer: B
Rationale: The correct answer is B: Linnaeus. Linnaeus developed the binomial system of nomenclature in the 18th century. This system uses a two-part naming system consisting of the genus and species name to classify and identify organisms. Linnaeus's contribution revolutionized the way organisms are named and classified in the field of biology. Other choices are incorrect as Pasteur is known for his work in microbiology, Martini is not associated with the development of binomial nomenclature, and Jenner is known for developing the smallpox vaccine.
Agglutination reaction is one of the following
- A. Ascoli ring test
- B. Western blot
- C. ELISA
- D. Reaction type Gruber
Correct Answer: A
Rationale: The correct answer is A: Ascoli ring test. Agglutination reaction in the Ascoli ring test is characterized by the formation of a visible ring at the interface of antigen and antibody. This reaction specifically tests for the presence of specific antibodies against antigens in serum, indicating a recent or current infection. The other options, Western blot, ELISA, and Reaction type Gruber, do not involve the agglutination reaction. Western blot and ELISA are immunoassay techniques that detect specific antibodies or antigens, while Reaction type Gruber is not a recognized method in immunology. Therefore, the Ascoli ring test is the correct choice for a test involving agglutination reaction.