The ability to roll the tongue (R) is determined by a dominant gene while the recessive gene results in the ability to roll the tongue (r). A man and his wife can both roll their tongues and are surprised to find that their son cannot. Explain this by showing the genotypes of all three pesons.
I think both the mother and the father's genotypes are Rr (heterozygous).
And the child probably has a homozygous recessive trait (rr).
Am I right?
Please check!
Thanks!
The first sentence should read:
The ability to roll the tongue (R) is determined by a dominant gene while the recessive gene results in the inability to roll the tongue (r).
(INability)*
Yes, you are correct! Based on the information given, the ability to roll the tongue (R) is determined by a dominant gene, while the inability to roll the tongue (r) is determined by a recessive gene. The genotypes of the individuals can be represented as follows:
Father: Rr (heterozygous)
Mother: Rr (heterozygous)
Son: rr (homozygous recessive)
Since both the father and the mother have the dominant allele R, they are able to roll their tongues. However, they each carry the recessive allele r as well. When they have a child, there is a 25% chance that the child will inherit two recessive alleles (rr), resulting in the inability to roll the tongue, as seen in their son.
So, in this case, the child inherited the recessive allele (r) from both parents, resulting in his inability to roll his tongue.