Here's an example: two chickens have the phenotype of white feathers and brown feathers. What percentage of the chicks will have the recessive color? First, you have to see the parents' phenotypes. Draw a punnet square. Put one of the parent's phenotypes (w and B) on the top, and the other parent's (w and B) on the right side going down. Whichever trait is dominant (brown) MUST be capitalized. Then, cross the two parents. first box on the top left would read 'ww.' The one below it is 'Bw' (put the dominant first). The right top is 'Bw' and the one below it is 'BB'. So if there were 4 offspring, these would be their genotypes: 'ww', 'Bw', 'Bw', and 'BB'. The only offspring that would have the recessive trait is the 'ww' child, because dominant overpowers recessive. So 25% would have the recessive trait and 75% would have the dominant trait.
