In a plant tallness is dominant over dwarfness and red flower is dominant over white. Starting with the parents work out a dihybrid cross. What is standard dihybrid ratio? Do you think the values would deviate if the two genes in question are interacting with each other?
The standard dihybrid ratio is 9:3:3:1. In this case ratio is 9 tall red, 3 tall white, 3 small (dwarf) red, 1 small white.
Yes, there is change in the dihybrid ratio if genes interact. For example in case of complementary gene interaction it is 9:7.