Here's why:
* Heterozygous: This term literally means "different yoked". In genetics, it refers to having two different alleles (versions) of a gene.
* Dominant: This allele, if present, will be expressed, even if only one copy is present.
* Recessive: This allele will only be expressed if two copies are present.
Example: Let's say a gene controls eye color.
* Brown eyes (B) are dominant over blue eyes (b).
* A person with the genotype Bb (one brown eye allele and one blue eye allele) is a heterozygote and will have brown eyes.
