3.) If dwarfism is genetic-what are the possible genotypes of the parents? If dwarfism is chromosomal abnormality describe the abnormality.

The parental genotypes that cause dwarfism are RR, Rr, and rr:  if both parents are RR, they are homozygous dominant and all of their children will have dwarfism; if both parents are Rr, they are heterozygous dominant and 75% of their children will have dwarfism; if one parent is Rr (heterozygous) and one is RR (homozygous) all of their offspring will have dwarfism; If one parent is Rr and the other is rr, at least 50% of their children will have dwarfism.  A mutation in the growth factor, called FGFR3,  on Gene 3 is responsible for dwarfism.