ATI RN
Immune System Test Quizlet Questions
Question 1 of 5
A protein-protein interaction domain present both in TLR-4 and MyD88 is:
Correct Answer: B
Rationale: The correct answer is B: TIR. This is because both TLR-4 and MyD88 contain a Toll/interleukin-1 receptor (TIR) domain, which mediates protein-protein interactions in the Toll-like receptor signaling pathway. The other options, such as A (CARD), C (LRR), and D (Immunoglobulin-like domain), are not present in both TLR-4 and MyD88 and do not play a significant role in their interaction in the signaling pathway. This makes B the most appropriate choice as it accurately identifies the common protein-protein interaction domain between TLR-4 and MyD88.
Question 2 of 5
The rearrangement of gene segments that occurs randomly in B cell receptor genes and T cell receptor genes:
Correct Answer: C
Rationale: Step 1: Gene rearrangement in B cell and T cell receptor genes creates unique receptor proteins. Step 2: This diversity allows mature lymphocytes to recognize a wide range of antigens. Step 3: This process is crucial for adaptive immune response and antigen specificity. Step 4: Choices A and B do not accurately describe gene rearrangement. Step 5: Choice D is incorrect as gene rearrangement is specific to lymphocytes, not all cells in the body.
Question 3 of 5
Which represents a correct grouping with respect to the target of an immune response, immune response strength, and resulting health status?
Correct Answer: C
Rationale: Rationale: 1. Tumor antigens are non-self antigens that trigger a weak immune response due to immune tolerance. 2. Weak immune response against tumor antigens may lead to uncontrolled cell growth, resulting in cancer. 3. Strong immune responses are typically mounted against pathogens to clear infections. 4. Self-antigens should not trigger immune responses to prevent autoimmune diseases. 5. Transplanted organs can elicit strong immune responses leading to rejection, not acceptance. Summary: A - Incorrect: Self-antigens should not elicit immune responses to prevent autoimmune diseases. B - Incorrect: Pathogens typically trigger strong immune responses to clear infections, not recurrent ones. D - Incorrect: Transplanted organs often lead to strong immune responses and rejection, not acceptance.
Question 4 of 5
Which of the following is a molecule that inhibits T cell activation, is highly expressed in Tregs and is used in a recombinant (synthetic) form to treat some autoimmune diseases?
Correct Answer: B
Rationale: The correct answer is B: CTLA-4. CTLA-4 inhibits T cell activation by binding to CD80/CD86 on antigen-presenting cells, preventing the co-stimulatory signal required for T cell activation. It is highly expressed in Tregs, which suppress immune responses. Recombinant CTLA-4 (e.g., abatacept) is used to treat autoimmune diseases by blocking T cell activation. Explanation for other choices: A: CD86 is a co-stimulatory molecule that activates T cells, not inhibits them. C: MHC class II molecules present antigens to T cells, they do not inhibit T cell activation. D: CD4 is a co-receptor that helps T cells recognize antigens presented by MHC class II molecules, it does not inhibit T cell activation.
Question 5 of 5
During the course of an immune response to a given antigen, affinity maturation results in survival of:
Correct Answer: B
Rationale: Rationale: 1. Affinity maturation is the process where B cells produce antibodies with increased affinity for the antigen over time. 2. B cells whose antibodies bind the antigen more strongly have higher affinity. 3. Survival of B cells with higher affinity antibodies is crucial for effective immune response. 4. A is incorrect as rate of antibody secretion doesn't necessarily correlate with affinity. 5. C is incorrect as T cells are not directly involved in affinity maturation of antibodies. 6. D is incorrect since T cells are not affected by affinity maturation in the context of this question.