The gene for tongue rolling is dominant. The mother's genotype is Tt and the father's genotype is Tt. What are the chances that he will be able to roll his tongue?

25% chance

50% Chance

75% chance

100% chance

The chances that the person will be able to roll his tongue has a 75% chance.

The way how you can calculate this is to make all the time:

Tt from the father and Tt from the mother

their offspring would have TT, Tt, Tt, tt

You see that out of the four genetic offspring, three time there is a T present - this means there is a 75% chance of the ability to roll the tongue.