You are given three homozygous strains of siamese fighting f

You are given three homozygous strains of siamese fighting fish with different phenotypes (blue, red #1, red #2). You make crosses, with the results shown below (reciprocal crosses give the same results).  

parents           offspring

blue   x    red #1           all green
blue   x    red #2       ½ blue    ½ green
green F1 x green F1    91 green    29 blue    42 red

What is the genotype of the original red #1 parent

Solution

Answer

R/R;B/B

Since there are only 2 alleles & three phenotypes (blue, red #1, & red #2), we must be dealing with incomplete dominance. So the red #1 parent is homozygous red (RR ) and blue (BB).