Step-by-step explanation:
Mendel's observation of 408 tall plants and 415 short plants suggests that he was working with a monohybrid cross between two heterozygous parents. This means that both parents carried one dominant allele for tallness (T) and one recessive allele for shortness (t).
Let's use Punnett squares to determine the possible genotypes of the parents and their offspring:
T = dominant allele for tallness
t = recessive allele for shortness
Possible genotypes for each parent:
Tt (heterozygous)
Punnett square for the cross between the two parents:
| T | t
--|----|---
T | TT | Tt
t | Tt | tt
The offspring of this cross will inherit one allele from each parent, resulting in the following genotypes and phenotypes:
TT (tall)
Tt (tall)
Tt (tall)
tt (short)
We know that the phenotypic ratio of the offspring was approximately 3:1 tall to short, which suggests that there were more tall offspring than short. This means that one of the parents must have been homozygous dominant (TT) and the other heterozygous (Tt), since the dominant allele is required for tallness.
Therefore, the genotypes of the parents were most likely:
TT (homozygous dominant)
Tt (heterozygous)
This cross would result in the following offspring:
100% Tt (tall)