Photo by Alexander Dimitrov on Unsplash[/caption]
Some alleles are recessive and dominant depending on whether they're expressed or not.
- Since human cells carry two copies of each chromosome, they have two versions of each gene.
- There are different versions of a gene, called alleles.
- They can either be dominant or recessive.
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Image by: Genome Research Limited[/caption]
Dominant Alleles
- Dominant alleles show their effect, even if the organism only has one copy of each allele (even if the organism is heterozygous for that allele).
- For example, the allele for brown eyes is dominant so you only need one copy of the brown eye allele to have brown eyes.