Question

Two tongue-rollers have 12 children. 8 of their children can roll their tongues and 4 cannot. Make an argument about the genotype of each of the parents and use a punnett square to explain your reasoning.

Answer 1

Let  the  dominant gene  for  tongue rolling  be  R  while  the  receive gene  be r. Therefore the  genotype  of  the  parent  is  heterogeneous  that  Rr  x Rr  since   they are  having  children  who  are  not  able  to  roll  the  tongue.The  punnet   square  is  as  follows.

Answer 2

If capital T is dominant trait of tongue-rolling, then little t is recessive trait of no-tongue rolling. For 8 children to roll their tongues (TT or Tt) and 4 children who can't (tt) both parents must be heterozygous (Tt).