Here's a breakdown:
* Alleles: Different versions of a gene.
* Genotype: The specific combination of alleles an individual possesses for a particular gene or set of genes. This is the genetic makeup of an organism.
* Phenotype: The observable characteristics or traits of an organism, which are determined by the genotype and environmental influences.
For example, if you have the alleles for brown eyes (B) and blue eyes (b), your genotype could be BB (brown eyes), Bb (brown eyes), or bb (blue eyes). Your phenotype would be either brown eyes or blue eyes, depending on your genotype.