Question

The cleft chin trait follows a dominant-recessive inheritance pattern with cleft chin being the dormant trait. john is heterozygous for a cleft chin as is his wife betty. john and betty have three kids all of which have a cleft chins. according to punnett square prediction what is the likely hood that their next child will have a cleft chin? 100% chance because the mother and father both have cleft chins 25% chance the same probability for all subsequent children 75% chance the same probability for all subsequent children 0% because the three pervious children have cleft chins already

Answer 1

Let's say that the genotype of the couples are:

Cc and Cc. Notice that one is capital and the other is not. This is what shows that they are heterozygous. We put this now in a Punnet Square:
    C   c
C CC Cc
c  Cc  cc

This means that there is a 75% chance that their children will have a cleft-chin and 25% will not.

The probability is the same with each off-spring. So the answer would be 75% chance the same probability for all subsequent children.