Question

Immunoglobulin heavy-chain gene consists of _______ segments, whereas the immunoglobulin light-chain gene consists of _______ segments.

a. kappa; lambda
b. VDJ; VJ
c. VJ; VDJ
d. P; N
e. RAG-1; RAG-2

Answer 1

The immunoglobulin heavy-chain gene consists of VDJ segments, whereas the light-chain gene consists of VJ segments, contributing to antibody diversity.

Step-by-step explanation:

The immunoglobulin heavy-chain gene consists of VDJ segments, whereas the immunoglobulin light-chain gene consists of VJ segments. This genetic arrangement allows for the immense diversity of antibodies' antigen-binding sites. In germ-line B cells, heavy chain genetic rearrangement involves V (variable), D (diversity), and J (joining) segments, while light chain rearrangement involves only V and J segments.

Both kappa and lambda types of light chains exist, and the variable region of the light chain gene has 40 V and five J segments, leading to numerous combinations for unique B cell receptors. Similarly, the heavy chains can be of different types, like gamma, alpha, mu, epsilon, and delta, defining different classes of immunoglobulins.