It would be most likely that their children has blood type AB.
Yes. It needs all its parts to survive.
DNA is a long polymer with deoxyriboses and a phosphate backbone. Has four different nitrogenous bases: adenine, guanine, cytosine, and thymine. RNA is a polymer with a ribose and phosphate backbone. Four different nitrogenous bases: adenine, guanine, cytosine, and uracil.