In the human species, the ability to fold the tongue depends on a dominant gene (L); The gene that determines not being able to do it (straight tongue) is recessive (l). Knowing that Juan can fold his tongue, while Ana cannot do it and neither can Juan's father, what are the chances of Juan and Ana having a son who can fold his tongue? Make a Punnett square.
Based on the information given, Juan's genotype is Ll (heterozygous) and Ana's genotype is ll (homozygous recessive).
When they have a child, there are two possible combinations of their alleles:
- 50% chance of the child being Ll (heterozygous, able to fold the tongue)
- 50% chance of the child being ll (homozygous recessive, unable to fold the tongue)
Therefore, there is a 50% chance that Juan and Ana will have a son who can fold his tongue.
Punnett square:
| | L | l |
|-----|------|------|
| L | LL | Ll |
| l | Ll | ll |