Double eyelids and single eyelids are the two most common types of human facial features. Do you know that?/You know what? Do you know that?/You know what? Double eyelids are dominant genes, while single eyelids are recessive genes. In this paper, the genetic characteristics of double eyelids and single eyelids will be discussed in depth to help readers better understand the mystery of biological inheritance.

Dominant genes and recessive genes

Double eyelids are dominant genes, while single eyelids are recessive genes. This means that the double eyelid gene is more easily expressed in the family.

Family inheritance

If there are members with double eyelids in the family, other members are likely to inherit this valuable genetic feature. Because on the stage of heredity, it is always easier for the "protagonist" to get the opportunity to "show his face".

Genetic law

If both parents have single eyelids, their children may still inherit the double eyelid gene and become the "inheritor" of the lucky dominant gene. This is because the double eyelid gene is dominant, while the single eyelid gene is recessive.

Genotype analysis

If the mother has a single eyelid and carries aa genotype, the father may be Aa or AA genotype. If their child has a single eyelid, it means that the father must be Aa genotype. Because the mother can only provide the small A gene, and the child has a single eyelid, which is the aa genotype, which means that the father provides the small A gene.