Here's how it works:
* Dominant allele: This allele is expressed even when only one copy is present. It's represented by a capital letter (e.g., 'R' for round seeds).
* Recessive allele: This allele is only expressed when two copies are present. It's represented by a lowercase letter (e.g., 'r' for wrinkled seeds).
For example, in Mendel's experiments with pea plants, the allele for round seeds (R) was dominant over the allele for wrinkled seeds (r).
* RR: Round seeds (homozygous dominant)
* Rr: Round seeds (heterozygous)
* rr: Wrinkled seeds (homozygous recessive)
So, even if a plant has one dominant allele (R) and one recessive allele (r), it will still express the dominant trait (round seeds).
