Height of spikeweed plants results from polygenic inheritance. Three genes control height, and each dominant “height” allele adds 5cm to the base height of the plant which is 10cm (i.e. a plant with no “height” alleles is 10cm tall). If a plant is homozygous “tall” at each locus the plant will be 40cm tall. A 40cm plant is crossed with a 10cm plant to produce F1 progeny. How tall are the plants in the F1 generation?

How many phenotypic classes (different heights) will there be in the F2 generation (a general answer is sufficient – you do not need to do the 64-square Punnett square)?