For the rose plants, considering the trait "presence of thorns" there are two possible phenotypes:
- Has thorns
- Does not have thorns
The alleles that code for this trait are:
R → the plant has thorns
r → the plant doesn't have thorns
A rose plant has no thorns and its genotype presents two alleles for the trait, this means that its genotype is "rr"
So,
- This rose plant's genotype for the thorn gene is rr.
- This rose plant does not have thorns. This is the plant's phenotype for the thorns trait.
→ The plant has two identical alleles for the trait, which means that it is homozygous for the thorns trait.
-This r