Question

Tongue rolling is a dominant trait. If two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue?

Answer 1

Answer:

0

Explanation:

Let's assume that the gene coding for tongue rolling is encoded by letter T.

The allele for tongue rolling (T) is dominant over the allele for inability to roll the tongue (t).

In a cross between two homozygous dominant individuals (TT) i.e. they have the same dominant allele in their genotype and hence, they can both roll their tongues.

(See attached image)

The cross will produce four possible offsprings, in which all will possess a homozygous dominant genotype i.e. all will be phenotypically able to roll their tongues. Hence, in the case of the child, the child will be able to roll his tongue.

The probability or chance that the child will be unable to roll his tongue is 0. Since there is none.