CHS PRACTICE EXAM (CERTIFIED HISTOCOMPATIBILITY SPECIALIST) EXAM QUESTIONS & ANSWERS 2025/2026

CHS PRACTICE EXAM (CERTIFIED HISTOCOMPATIBILITY SPECIALIST) EXAM QUESTIONS & ANSWERS 2025/2026 Which of the following is not a secondary lymphoid organ? a. Spleen b. Thymus c. Lymph nodes d. Liver e. Tonsils - ANS-Thymus Primary lymphatic organs are where lymphocytes are formed and mature. stem cells to divide and mature into B- and T- cells: There are two primary lymphatic organs: the red bone marrow and the thymus gland. Which of the following is not a component of the reticuloendothelial cell system? a. Microglial cells b. Kupffer cells c. Langerhans cells d. Neutrophils e. Monocytes - ANS-Neutrophils Macrophages = tissue Monocytes = blood Kupffer cells = liver Microgial cells = nervous system Langerhans = skin Not = endothelial cells, fibroblasts, and most leukocytes Opsonization is a term to describe what? a. Lysis of bacteria b. Coating of bacteria c. Ingestion of bacteria d. Killing of bacteria e. Phagocytosis - ANS-Coating of bacteria Antibody opsonization is the process by which a pathogen is marked for ingestion and eliminated by a phagocyte. Which of the following does not describe a role of antibodies in host defense? a. They serve as a bridge between bacteria and phagocytes b. They lyse bacteria c. They enhance complement binding to the bacterial cell wall d. They prevent viruses from infecting cells e. They bind pathogens in mucus secretions - ANS-They lyse bacteria MHC Class I and II molecules differ in all of the following except a. Types of T cells they stimulate b. Types of cells they are expressed on c. Which chromosome they are located on d. Types of antigens they present e. Whether or not they have foreign peptides in the antigen-binding groove - ANS-Which chromosome they are located on The primary role of the proteasome in antigen presentation is to a. Prevent premature folding of MHC class I molecules b. Process cytoplasmic proteins c. Degrade recycled MHC molecules d. Bind HLA-DM in the endosome e. Chaperone peptides to the cell surface - ANS-Process cytoplasmic proteins The main function of the proteasome is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Peptides that bind to MHC class I molecules differ from peptides that bind to MHC class II molecules in all except which of the following ways? a. They are shorter b. They were processed by different proteases c. They anchor in the middle instead of the end of the MHC molecule d. They interact with different subsets of T cells - ANS-...