Can YOU curl your tongue up on the sides?
Scientists Debunk Familiar Tongue-Rolling Lore | HuffPost Impact
We are pretending that tongue-curling in humans is a dominant genetic trait.
Suppose a man who is Tt for tongue-curling marries a woman who is also Tt for this trait. What are the possible genotypes and phenotypes of their children, and the percent chance for each?
If tongue-curling in humans is considered a dominant genetic trait, the possible genotypes and phenotypes of the children of a man who is Tt for tongue-curling and a woman who is also Tt for this trait are as follows:
Genotypes:
- TT: Homozygous dominant (tongue-curling)
- Tt: Heterozygous (tongue-curling)
- tt: Homozygous recessive (no tongue-curling)
Phenotypes:
- Tongue-curling: TT, Tt
- No tongue-curling: tt
To determine the percent chance for each genotype and phenotype in their children, we can use a Punnett square:
T t
---------------
T | TT Tt
T | TT Tt
From the Punnett square, we see that there is a 25% chance of having a child with the TT genotype (tongue-curling), a 50% chance of having a child with the Tt genotype (tongue-curling), and a 25% chance of having a child with the tt genotype (no tongue-curling).
In terms of phenotypes, there is a 75% chance of having a child who can curl their tongue (either TT or Tt genotype), and a 25% chance of having a child who cannot curl their tongue (tt genotype).