Answer:
The false option is "The constant region of a heavy chain is the same for all antibodies".
Step-by-step explanation:
The antibody are quaternary strucrured Y shaped proteins composed of two light chains and two heavy chains. These cahins are joined by sulphide bridges that allows them to bind to specific antigen.
There is a misleading conception found that the "constant region" is same in all antibodies. The constant region of antibodies is responsible for the specific immune response of antibodies. The constant region is same in group of antibodies or we can say antibodies are divided into different groups based on the constant region such as IgG, IgM, IgE, IgD and IgA. The constant domain in the heavy chain H of the antibodies from any of these group would be same.
So The constant region would be same in antibodies of same group but it would be different in the antibodies of different groups.