What proportion of blue flowed progeny plants will breed true if self-fertilized?
The blue flower is heterozygous since it contains the alleles for blue and pink. Lets call the dominant allele, blue, B and pink, b. So crossing Bb with itself Bb yields: BB, Bb, Bb, bb so about 3/4 should be blue and 1/4 pink. Our theoretical is similar to actual data. Of the blue (BB, Bb, Bb) 2/3 if self fertilized will still yield pink. But 1/3 (BB) will breed true blue!
