ATI LPN
Hematologic System Questions Questions
Question 1 of 4
In the immune response to a hapten-protein conjugate, in order to get anti-hapten antibodies it is essential that
Correct Answer: B
Rationale: The correct answer is B because helper T cells play a crucial role in activating B cells to produce antibodies. In this scenario, the protein component of the hapten-protein conjugate must be recognized by helper T cells to initiate the immune response. This recognition leads to the activation and differentiation of B cells into plasma cells that secrete anti-hapten antibodies. Choices A, C, and D are incorrect because the focus should be on the protein component, not the hapten or suppressor T cells, for the production of anti-hapten antibodies.
Question 2 of 4
Which one of the following does NOT contain C3b?
Correct Answer: C
Rationale: The correct answer is C because classic-pathway C3 convertase does not contain C3b. In the classical pathway, C3 convertase is formed by the cleavage of C4bC2a, which does not involve C3b. A: classic-pathway C5 convertase contains C3b as it is formed by the binding of C4b2a3b complex to C5. B: alternative-pathway C5 convertase contains C3b as it is formed by the binding of C3bBb3b complex to C5. D: alternative-pathway C3 convertase contains C3b as it is formed by the binding of C3bBb complex to C3.
Question 3 of 4
An Rh-negative woman married to a heterozygous Rh-positive man has three children. The probability that all three of their children are Rh-positive is
Correct Answer: C
Rationale: Certainly! The Rh factor follows Mendelian inheritance. The Rh-negative woman is homozygous Rh-negative (rr) and the Rh-positive man is heterozygous (Rr). The Punnett square for their offspring shows a 1/2 chance of each child being Rh-positive (Rr). Therefore, the probability of all three children being Rh-positive is (1/2)^3 = 1/8, making choice C the correct answer. Choices A, B, and D are incorrect because they do not consider the specific genetic inheritance pattern of the Rh factor in this scenario.
Question 4 of 4
An individual who is heterozygous for Gm allotypes contains two allelic forms of IgG in serum, but individual lymphocytes produce only one of the two forms. This phenomenon, known as 'allelic exclusion,' is consistent with
Correct Answer: A
Rationale: The correct answer is A because allelic exclusion in this context refers to the phenomenon where only one allelic form of a gene is expressed in a particular cell. In this case, the individual is heterozygous for Gm allotypes, meaning they have two different allelic forms of IgG. Since the individual lymphocytes produce only one of the two forms, it suggests that the heavy-chain gene on one chromosome has undergone rearrangement, leading to the expression of a single form of IgG. This supports choice A. Choices B, C, and D are incorrect because they involve either both chromosomes or light-chain genes, which are not relevant to the scenario described.