To solve this genetics problem, we need to understand the inheritance of the tongue-rolling trait. Let's denote the allele for being able to roll the tongue as "R" (dominant) and the allele for not being able to roll the tongue as "r" (recessive).
The man who cannot roll his tongue has the genotype "rr," since he expresses the recessive trait. The woman who is heterozygous for tongue-rolling has the genotype "Rr."
When we create a Punnett square to visualize the potential offspring, we cross "Rr" (mother) with "rr" (father):
R | r
-----------------
r | Rr | rr
-----------------
r | Rr | rr
From the Punnett square, we can see the possible genotypes of the offspring:
- 50% (2 out of 4) will be "Rr", which means they can roll their tongue (tongue rollers).
- 50% (2 out of 4) will be "rr", which means they cannot roll their tongue (non-tongue rollers).
So, the complete sentences would be:
A man who cannot roll his tongue has children with a woman who is heterozygous for tongue-rolling. Their children will have a 50% chance of being a tongue roller and a 50% chance of not being a tongue roller.