Answer:
co dominance
Step-by-step explanation:
codominance is a type of inheritance in which both allels are dominat over each other and the two allels are expressed to an equal degree in an offspring,that is why the cross between yellow and blue snake give another green colour offsprings in stead of giving all blue or all yellow offsprings depending on which allel is dominant.
as example we can take human blood group AB which is inherited from blood group A and B and both allel A and B are dominant over each other.
I hope it helped you!