Microbiology

Which one of the following statements best describes immunoglobulin structure?

The amino acid sequence variation of the heavy chains is different than that observed in light chains

In humans, there are approximately twice as many Ig molecules with k and l chains

In the three-dimensional structure of Ig, there is little, if any, flexibility in the hinge region between the Fc and two Fab poions

IgM is a monomeric structure