g Antibodies are proteins that recognize a particular antigen and are produced by specialized B cells. Antibodies consist of polypeptide chains linked together in a Y‑shaped formation. How many heavy chains and how many light chains does an antibody have?

2 heavy chains and 2 light chains

Explanation:

Antibodies belong to the eponymous immunoglobulin superfamily and they are majority made up of 2 heavy (H) and 2 light (L) chains. Where the heavy chains is made up of 3 or 4 C domains while the L chain consist of either a k or a lambda chain.