Final answer:
The kappa light chain region of an immunoglobulin (Ig) is coded for by A. chromosome 2, which is essential for the immune system's ability to produce antibodies with unique antigen-binding sites.
Step-by-step explanation:
The chromosome that codes for the kappa light chain region of an immunoglobulin (Ig) is chromosome 2. The kappa light chains are an essential part of the immune system's ability to recognize and neutralize pathogens. Kappa light chains consist of two regions, the variable (Vk) and constant (Ck) regions, which are pivotal in creating the diversity necessary for the immune system to recognize a wide array of antigens. The gene rearrangement mechanism involving the variable (V), joining (J), and constant (C) gene segments lead to the production of a unique kappa light chain with a specific antigen affinity.
Each immunoglobulin molecule can possess either two kappa or two lambda light chains but not both. In humans, the ratio of kappa to lambda light chains is approximately 2:1. During the maturation of B cells, which are a type of immune cell, a process called V(D)J recombination allows each B cell to produce antibodies with unique antigen-binding sites.
Summing up, the correct answer to the question is:
- chromosome 2 codes for the kappa light chain region of an immunoglobulin (Ig).