Alleles
- A gene is a short length of DNA found on a chromosome that codes for a particular characteristic (expressed by the formation of different proteins)
- Genes exist in alternative forms called alleles
- Alleles are variations of the same gene
- As we have two copies of each chromosome (one from each parent), we have two copies of each gene and therefore two alleles for each gene
- One of the alleles is inherited from the mother and the other from the father
- This means that the alleles do not code for the same thing
- For example, an individual has two copies of the gene for eye colour but one allele could code for brown eyes and one allele could code for blue eyes
- Having alleles give rise to differences in inherited characteristics and variation within species
