Question

The Major Histocompatibility Complex (MHC) is a set of proteins expressed on the surface of antigen presenting cells that recognize and bind to pieces of antigens so that they can be presented to the appropriate T cell. Not only is the expression of these proteins controlled by more than one gene (polygenic), but individuals with different alleles for MHC proteins are heterozygous for that gene. What advantage does the MHC proteins being polygenic and codominant offer to the individual?

A There will be a lower level of immune rejection for this individual should they receive a blood or organ transplant.There will be a lower level of immune rejection for this individual should they receive a blood or organ transplant.
B There will be an increased resistance to HIV infection, as the T cells will be less likely to be invaded by the virus.There will be an increased resistance to HIV infection, as the T cells will be less likely to be invaded by the virus.
C There is a larger variety of MHC proteins that can be expressed on the cell surfaces of their immune cells, providing a wider opportunity to recognize and attack pathogens.There is a larger variety of MHC proteins that can be expressed on the cell surfaces of their immune cells, providing a wider opportunity to recognize and attack pathogens.
D There is an increased opportunity for anaphylaxis, as presenting a wider variety of MHC proteins on the cell surfaces of immune cells will result in a body-wide response to antigens.

Answer 1

There is a larger variety of MHC proteins that can be expressed on the cell surfaces of their immune cells, providing a wider opportunity to recognize and attack pathogens. Hence the correct option is c.

The polygenic and codominant nature of Major Histocompatibility Complex (MHC) proteins confers a significant advantage to individuals by promoting a diverse immune response. MHC proteins, expressed on the surface of antigen-presenting cells, play a crucial role in recognizing and binding to fragments of antigens, facilitating their presentation to T cells. The polygenic nature means that the MHC proteins are controlled by multiple genes, contributing to a wide array of possible alleles. Additionally, the codominant expression allows individuals to inherit different alleles from each parent, resulting in heterozygosity.

This diversity in MHC proteins offers a broader spectrum of antigen presentation on the cell surfaces of immune cells. As a result, the immune system becomes capable of recognizing and responding to a wide variety of pathogens. This heightened diversity enhances the individual's ability to mount effective immune responses against a range of infectious agents. It provides a level of adaptability that is advantageous in defending against a multitude of pathogens, ultimately contributing to the robustness and efficiency of the immune system. Hence the correct option is c.