* Two copies of the recessive allele are needed for the trait to be expressed. This means that an individual must inherit one copy of the recessive allele from each parent.
* The recessive allele is masked by the dominant allele. If an individual inherits one copy of the dominant allele and one copy of the recessive allele, they will express the trait associated with the dominant allele.
Here's an analogy: Think of a dominant allele as a "strong" version of a gene and a recessive allele as a "weak" version. If you have one strong and one weak version, the strong version will be the one you see. You only see the weak version if you have two weak versions.
Example:
* Brown eyes are dominant over blue eyes. This means that if you have one brown eye allele and one blue eye allele, you will have brown eyes. To have blue eyes, you must inherit two blue eye alleles, one from each parent.
Key points to remember about recessive genes:
* Individuals can be carriers of recessive genes. This means they have one copy of the recessive allele but don't express the trait because they also have a dominant allele.
* Recessive traits can skip generations. This is because carriers can pass on the recessive allele without expressing the trait themselves.
* Many genetic disorders are caused by recessive genes. Examples include cystic fibrosis, sickle cell anemia, and Tay-Sachs disease.
