Amother that carries the colorblind allele and a father with normal vision can have children that are only a) normal boys and normal girls. b) colorblind girls and colorblind boys. c) normal boys, normal girls, and colorblind girls. d) normal girls, normal boys, and colorblind boys.

If the father had the gene BB (purebred & not carrying colourblind allele), then the answer will be a). All of their children will have normal vision with half of them carrying the colourblind allele.
If the father had the gene Bb (hydrid & carrying colourblind allele), then the answer will be d). 3/4 of their children would have normal vision whilst the last quarter would have colourblind males. This is due to them having to receive one colourblind allele from their mother on the X chromosome & one colourblind allele from their father on the Y chromosome.

The answer is telescope.