MHC and HLA Quiz: The Genetics of Tissue Typing

If MHC class I shows what is happening 'inside' a cell, then a killer cell must check it; if an MHC and HLA quiz identifies the CD8+ cell as the assassin, then the cytotoxic T cell is the one doing the scanning.

If the entire lesson focuses on identification and cell-surface markers, then the summary must involve 'self' vs 'non-self'; if MHC/HLA provides the physical proof of identity, then answer a is the best summary.

If the MHC is like a constant reporter, then it shows whatever is inside the cell; if the cell is healthy, then the MHC shows 'self' proteins; if the immune system is working, it ignores these 'good' reports. Thus, the statement is false.

If an MHC and HLA quiz asks about the 'exogenous' pathway, then it is asking about things from outside; if the cell swallows the germ (phagocytosis) and chops it up, then it can load the pieces onto the MHC II.

If a cell is missing its 'ID badge' (MHC), then it is suspicious; if natural killer cells are programmed to kill any cell that cannot show its 'self' badge, then they will destroy the hiding cancer cell.

If 'leukocyte' means white blood cell and 'antigen' is something the immune system reacts to, then the name describes where they were found; if an MHC and HLA quiz asks about history, then the name fits the discovery.

If scientists have mapped the location of the MHC/HLA gene family, then they have found a specific 'cluster'; if that cluster is found on the short arm of the sixth chromosome, then answer a is correct.

If 'histo' relates to tissue and 'compatibility' relates to getting along, then the name describes how tissues match; if this is the primary protein system for matching, then the name is Major Histocompatibility Complex.

If HLA markers are built based on the genes you inherit from your parents, then people with identical DNA will have identical markers; if identical twins share 100% of their DNA, then the statement is true.

If different HLA shapes catch different germ pieces, then a variety of shapes is safer; if an MHC and HLA quiz asks about survival, then having many types ensures some people can always 'see' and fight a new germ.

If every person has a different 'ID badge' (MHC), then a new organ's badge will look 'wrong' to the patient; if the immune system sees a 'wrong' badge, then it will attack the new organ.

If MHC proteins are made using instructions from the DNA in the nucleus, then a cell without a nucleus cannot make them; if an MHC and HLA quiz asks why red blood cells are unique, then the lack of a nucleus is the reason they lack MHC.

If a cell is designed to 'eat' germs and report them to the 'commanders' (helper T cells), then it must have the MHC II tray; if macrophages, dendritic cells, and B cells are those reporters, then they are the correct choices.

If a virus can infect almost any cell with a nucleus, then those cells need a way to signal for help; if MHC class I is the 'internal health' signal, then it must be present on almost all nucleated cells.

If you are taking an MHC and HLA quiz, then you learn that HLA is just the specific name for the MHC proteins found in humans; if they are the same system, then the statement is true.

If the T cell identifies the piece as 'non-self,' then it must react; if it releases cytokines (alarm), multiplies (cloning), and attacks, then these are the correct immune responses.

If the MHC markers match the ones the immune system was 'trained' on, then the system knows the cell belongs to the body; if it identifies its own cells, then it is performing self-recognition.

If the tray (MHC) serves a 'meal' (the germ piece) to a 'judge' (the T cell), then the analogy helps in an MHC and HLA quiz; if this represents the presentation of the antigen, then 'platter' is the correct analogy.

If an MHC and HLA quiz asks about the shape of the tray, then it focuses on the 'pocket'; if the germ piece is a short chain of amino acids (a peptide), then it is held in the peptide-binding groove.

If every person has a unique set of these proteins, then they work like a passport or badge; if the immune system 'reads' these badges to see if a cell is 'self,' then they act like ID cards.