Select the true statements regarding antibody (specifically, immunoglobulin G) structure.

a. Both the Fab and Fc fragments have variable domains.
b. The antigen‑binding site is formed as a combination of variable domains from one heavy and one light chain.
c. The heavy and light chains are linked by noncovalent and disulfide bonds.
d. The antigen‑binding site is located in the Fab fragment.
e. Only the Fc fragment has constant domains.

Option b, c and d are correct

Explanation:

The heavy and light chains of the antibody or IgG are linked together by non co-valent and disulfide bonds.

The antigen-binding place of the complex is formed by the combination of variable domains which is formed by the combination of one light chain and one heavy chain. Antigen binding site, also known as paratope.

The antigen binding site in an antibody is located only on Fab arm of the IgG which functions by binding to the antigen.

the backbone of the dna and rna compound is sugar phosphate.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.