Red-green colour blindness appears due to

All sons of a couple are colourblind because

Sickle cell anaemia disorder arises due to

One of the genes present exclusively on the $X$-chromosome in humans is concerned with

Testing for $\beta$-thalassemia should be done before marriage.

With the help of the given pedigree, find out the probability for the birth of a child having no disease and being a carrier (has the disease mutation in one allele of the gene) in the $F_3$ generation.