Answer:
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.
