Based on the information below, answer the following three questions, assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait;
the inability to roll the tongue is a recessive trait."
If an individual homozygous dominant for this trait has a child with an individual who cannot roll his tongue, what is the chance that the child will have a heterozygous genotype?

100%

Explanation:

Let’s represent the dominant tongue rolling trait as: R

and the recessive trait as: r

A homozygous individual will have the same alleles i.e. RR (for dominant), rr (for recessive). Note that Rr is heterozygous.

An individual homozygous dominant for tongue rolling has the alleles RR

and an individual who cannot roll his tongue has rr, that is homozygous recessive .

To determine the trait of their offspring, we'll cross their traits

Crossing the two :

RR  x  rr

Rr, Rr, Rr, Rr

All the offspring will inherit the dominant R and the recessive r from both parents.

Therefore, there is a 100%  chance that the child will have a heterozygous genotype.

the actual answer was 160934