Here's a breakdown:
* Alleles: Different versions of a gene.
* Genotype: The genetic makeup of an organism, the specific combination of alleles it has.
* Phenotype: The observable characteristics of an organism, determined by the genotype and environmental influences.
Example:
Let's consider eye color. The gene for eye color has multiple alleles, including brown (B) and blue (b).
* Genotype: A person with the genotype BB or Bb will have brown eyes.
* Phenotype: Brown eyes.
In essence, the phenotype is the physical expression of the genotype.
