Number of variable regions on each light and heavy chain of an antibody -: (A) 1, (B) 2, (C) 3, (D) 4
Answer is A. A light chain has two successive domains: one constant domain and one variable domain. Heavy chain with one variable (VH) domain followed by a constant domain (CH) Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:94