Two true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high.

a)What is the contribution of each dominant allele to the phenotype in cm?

b)The F1 from (c) is then crossed to give an F2. What proportion would you expect in the F2 of each extreme phenotype?

c) In a cross between a 29cm plant and a 20cm plant what would be the genotypes giving the lowest number of different phenotypes? specify the phenotypes observed.