Freckles are a dominant trait. Freckles come from genes and the sun and are most often seen on people with light-colored skin.Know More
Freckles are a result of exposure to the ultraviolet light that comes from the sun. Melanin is made when the sun's rays hit the skin as a way of shading and protecting it. If a person produces melanin evenly, it's called tanning. Those people who produce it in clumps tend to freckle.
Scientists are not sure as to why some people tan and others freckle. They suspect it's because the gene that causes freckles, called MC1R, doesn't work well in some people. In those people whose MC1R gene fails on two levels, red hair and freckles are prominent traits. It is more common for the gene to fail on the level that causes freckles than it is to fail and produce both red hair and freckles.Learn More
The father does not carry the gene for non-identical twins, as releasing more than one egg at a time is a trait that runs in the maternal line. There is no evidence suggesting that identical twins run in families. Women who experience a multiple pregnancy are at higher risk of certain complications.Full Answer >
A genetic characteristic of an individual is any trait that can be attributed to a hereditary cause, coded for in inherited DNA. Any other trait is derived from environmental causes, either while within the womb or outside of it. It can be very difficult to determine if a characteristic is genetic, congenital but not genetic or acquired after birth.Full Answer >
Rh factor is an inherited trait that does not affect health but sometimes affects pregnancies of Rh-negative mothers carrying Rh-positive babies, states Mayo Clinic. Rh factor is a protein located on the red blood cells. Individuals with the protein are Rh positive; those without it are Rh negative.Full Answer >
The most common example of a recessive gene is eye color. Brown eyes are dominant, while gray, green, hazel and blue eyes occur due to recessive genes.Full Answer >