a. If a person has the genetic combination Tt. Then, half of his/her genes are the dominant trait T and the other half are the recessive trait t. So, his/her genes can be represented by 0.5T + 0.5t. If both parents have the genetic combination Tt, then the outcomes for their children can be modeled by the sum of the square: b. There are four total outcomes. For children to have two dominant genes, they would have TT, which is a 25% probability. For children to have one dominant gene, they would have Tt, which is a 50% probability. For children to have two recessive genes, they would have tt, which is a 25% probability.