Name 3 signs or symptoms of immune thrombocytopenia purpura. (Choose one)

Correct Answer: B

Rationale: The correct answer is B: Easy bruising. Immune thrombocytopenia purpura is characterized by low platelet count, leading to easy bruising. Fever (A) and joint pain (C) are not typical symptoms of ITP. Hair loss (D) is not associated with this condition. Easy bruising is a key sign due to decreased platelets preventing proper blood clotting.

Correct Answer: C

Rationale: The correct answer is C because minor histocompatibility antigens, which are not matched in a 2-haplotype MHC-matched kidney transplant from a relative, can still trigger an immune response leading to graft rejection. This is why immunosuppression is still necessary. A: Graft-versus-host disease would not be a problem in this scenario as the recipient is receiving a kidney transplant, not bone marrow. B: This choice is redundant with the correct answer. Matching minor histocompatibility antigens is crucial for reducing the risk of rejection. D: Complement components do not play a significant role in graft rejection in this context.

Correct Answer: B

Rationale: The correct answer is B: vascular permeability. C3a and C5a are anaphylatoxins that can cause increased vascular permeability, leading to fluid leakage and inflammatory responses. They do not directly cause bacterial lysis (choice A), phagocytosis of IgE-coated bacteria (choice C), or aggregation of C4 and C2 (choice D). Increased vascular permeability is a key mechanism by which these complement proteins contribute to inflammation and immune responses.

Correct Answer: D

Rationale: The correct answer is D because the genes for the gamma chain and alpha chain are located on the same chromosome, making them linked genes. This is known as genetic linkage. The other choices (A, B, C) involve genes from different chromosomes or gene segments, so they are not linked genes. Genes that are physically close together on the same chromosome tend to be inherited together, which is the basis of genetic linkage analysis.

Correct Answer: A

Rationale: Activated helper T cells release various cytokines to regulate the immune response. Interleukin-1 is primarily produced by macrophages and monocytes, not helper T cells. It plays a role in inflammation and fever. Interleukin-2, interleukin-4, and gamma interferon are indeed released by activated helper T cells to stimulate immune responses. Therefore, choice A, interleukin-1, is the correct answer as it is not typically released by activated helper T cells.