Nokea
What is the primary mechanism by which innate immunity differentiates between self and non-self?
- A. Somatic recombination
- B. Recognition of PAMPs via PRRs
- C. Presentation of antigens by MHC molecules
- D. Production of antibodies
Correct Answer: B
Rationale: The correct answer is B: Recognition of PAMPs via PRRs. Innate immunity distinguishes self from non-self by recognizing Pathogen-Associated Molecular Patterns (PAMPs) via Pattern Recognition Receptors (PRRs). This recognition triggers an immediate response to eliminate potential threats. Choices A, C, and D are incorrect because somatic recombination is a process in adaptive immunity, MHC molecules present antigens for recognition by T cells in adaptive immunity, and antibody production is part of adaptive immunity involving B cells.
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Select the following disorders characterized by inflammation of bronchi.
- A. Asthma
- B. Bronchitis
- C. Emphysema
- D. Tuberculosis
Correct Answer: B
Rationale: Step-by-step rationale:
1. Bronchitis is characterized by inflammation of the bronchi, leading to coughing and mucus production.
2. Asthma involves inflammation and narrowing of the airways but is not specific to bronchi.
3. Emphysema is a lung disease involving damage to the air sacs, not specifically inflammation of bronchi.
4. Tuberculosis is a bacterial infection affecting the lungs, not primarily characterized by bronchial inflammation.
Summary:
Bronchitis is the correct answer as it specifically involves inflammation of the bronchi, while asthma, emphysema, and tuberculosis do not primarily exhibit this characteristic.
An example of a preformed chemical barrier is:
- A. Mucus
- B. Lysozyme
- C. Tight junctions in epithelial cells
- D. Cilia in the respiratory tract
Correct Answer: B
Rationale: Step-by-step rationale:
1. Lysozyme is an enzyme that destroys bacterial cell walls.
2. This action acts as a preformed chemical barrier against pathogens.
3. Mucus (choice A) is a physical barrier, not a preformed chemical one.
4. Tight junctions (choice C) and cilia (choice D) are structural components, not chemical barriers.
Summary:
- Choice B, Lysozyme, is correct as it actively targets and destroys pathogens.
- Choices A, C, and D are incorrect as they do not directly function as preformed chemical barriers.
What accurately describes passive acquired immunity (select all that apply)?
- A. Pooled gamma globulin
- B. Immunization with antigen
- C. Temporary for several months
- D. Immediate, lasting several weeks
Correct Answer: C
Rationale: Passive acquired immunity involves the transfer of antibodies from one individual to another, such as pooled gamma globulin, maternal immunoglobulins, and immediate protection that lasts for weeks to months.
A heart attack is
- A. damage to cardiac muscle
- B. Typically from a blocked coronary artery
- C. Death of brain tissue from blocked arteries in the head
- D. A & b
Correct Answer: D
Rationale: The correct answer is D because a heart attack, also known as a myocardial infarction, involves damage to the cardiac muscle due to a blocked coronary artery. Choice A is correct as it directly relates to the definition of a heart attack. Choice B is also correct as a blocked coronary artery is the main cause of decreased blood flow to the heart muscle leading to a heart attack. Choice C is incorrect as it refers to a stroke, which is the death of brain tissue due to blocked arteries in the head, not a heart attack. Therefore, A & B (choices A and B) are the correct options, making D the correct answer.
Who is credited with the discovery of phagocytosis?
- A. Edward Jenner
- B. Louis Pasteur
- C. Elie Metchnikoff
- D. Paul Ehrlich
Correct Answer: C
Rationale: The correct answer is C: Elie Metchnikoff. He is credited with the discovery of phagocytosis, the process in which certain cells engulf and digest foreign particles. Metchnikoff's research in the late 19th century laid the foundation for our understanding of the immune system. A: Edward Jenner is known for developing the smallpox vaccine. B: Louis Pasteur is famous for his work on germ theory and pasteurization. D: Paul Ehrlich is known for his contributions to immunology, such as developing the concept of antibodies and chemotherapy.