Nokea
Which isotype plays a major role in opsonization of antigens?
- A. IgM
- B. IgG
- C. IgA
- D. IgD
Correct Answer: B
Rationale: The correct answer is B: IgG. IgG plays a major role in opsonization by binding to antigens and marking them for phagocytosis. IgM is the first antibody produced in response to an infection but is not as effective in opsonization. IgA primarily protects mucosal surfaces. IgD is involved in the activation of B cells, not opsonization. In summary, IgG is the correct choice due to its specific role in opsonization compared to the other isotypes.
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Which classification of chemotherapy drugs is cell cycle phase–nonspecific, breaks the DNA helix which interferes with DNA replication, and crosses the blood-brain barrier?
- A. Nitrosureas
- B. Antimetabolites
- C. Mitotic inhibitors
- D. Antitumor antibiotics
Correct Answer: A
Rationale: Nitrosureas are cell cycle phase–nonspecific, disrupt DNA replication, and cross the blood-brain barrier.
The term 'lymphocyte repertoire' refers to:
- A. The range of antigen receptor specificities found in a lymphocyte population
- B. The variety of effector functions that result from an adaptive immune response
- C. Antigen receptor specificities found on a given lymphocyte
- D. The collection of daughter cells produced when a lymphocyte divides after activation
Correct Answer: A
Rationale: The correct answer is A because the term 'lymphocyte repertoire' specifically refers to the range of antigen receptor specificities found in a lymphocyte population. Lymphocytes are immune cells that play a crucial role in recognizing and responding to antigens, and their diverse antigen receptor specificities allow them to recognize a wide range of pathogens. This term does not refer to effector functions (B) or a single lymphocyte's receptor specificities (C). Additionally, it does not describe the collection of daughter cells produced after division (D), as the repertoire refers to the initial diversity of antigen receptors within a lymphocyte population.
Which of the following immunoglobulins is present normally in plasma at the highest concentration?
- A. IgG
- B. IgM
- C. IgA
- D. IgD
Correct Answer: A
Rationale: The correct answer is A: IgG. IgG is the most abundant immunoglobulin in plasma, comprising around 75% of total immunoglobulins. It is produced in response to infections and provides long-term immunity. IgM is the first antibody produced in response to an infection, but its concentration decreases over time. IgA is mainly found in mucosal areas and secretions. IgD is present in small amounts and its function is not fully understood. Thus, IgG is the correct answer due to its high concentration in plasma and important role in long-term immunity.
Priority Decision: On assessment of a central venous access device (CVAD) site, the nurse observes that the transparent dressing is loose along two sides. What should the nurse do immediately?
- A. Wait and change the dressing when it is due
- B. Tape the two loose sides down and document
- C. Apply a gauze dressing over the transparent dressing and tape securely
- D. Remove the dressing and apply a new transparent dressing using sterile technique
Correct Answer: D
Rationale: Loose dressings increase infection risk; replacing the dressing with sterile technique ensures safety.
Which of the following is an example of a live attenuated bacterial vaccine?
- A. Cholera
- B. Typhoid
- C. Anthrax
- D. Plague
Correct Answer: B
Rationale: The correct answer is B: Typhoid. Live attenuated vaccines contain weakened forms of the pathogen that can replicate in the host to stimulate a strong immune response without causing disease. Typhoid vaccine is an example of a live attenuated bacterial vaccine because it contains weakened Salmonella typhi bacteria. Cholera (A), Anthrax (C), and Plague (D) vaccines are not live attenuated bacterial vaccines; they are either killed/inactivated or subunit vaccines. Live attenuated vaccines provide longer-lasting immunity compared to other vaccine types.