What is double eyelid

summary

People with double eyelids have beautiful eyes, which can give people a good first impression. Whether double eyelids are related to human genetics, let's understand the problem of double eyelids.

What is double eyelid

First: double eyelid refers to the upper eyelid skin in the upper eyelid edge has a shallow groove, when you open your eyes, the skin below the groove moves up, and the skin above the groove is loose, hanging in the double eyelid groove and folding down. In order to form a pair of beautiful double eyelids, we must comprehensively consider the shape, width and upper eyelid swelling of the double eyelids.

Second, there is a biological genetic reason: double eyelid is a dominant gene, while single eyelid is a recessive gene. If the genes controlling single eyelid and double eyelid are big a and small a respectively, then the combination of AA and AA is double eyelid, and AA is single eyelid. According to this ratio, the ratio of double eyelid and single eyelid should be 3:1.

Third: finally, if the mother in a family is single eyelid, then she is AA gene, while the father may be AA or AA gene, but if their two children are single eyelid, then the father must be AA, because the mother can only provide small a gene, and the child is single eyelid, that is AA gene.

matters needing attention

From the above, we can learn that single and double eyelids are inherited. There is no need to worry about them. We can also reserve some knowledge, which is of great help to our future life.