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 about Molecular Biology & DNA
An ancestral trait is a genetic similarity passed down to subsequent generations, such as eye and skin color. Male pattern baldness and flushed cheeks are also considered ancestral traits.Full Answer >
A double recessive gene contains recessive alleles inherited from both parents. Alleles are variations of a gene controlling a particular characteristic such as eye color. The presence of both recessive alleles results in the expression of the recessive trait.Full Answer >
Dominant alleles are always expressed in the organism, while recessive traits tend to be expressed only when the dominant allele is not present. The relationship between dominant and recessive genes is described by the Law of Segregation. As related by About.com, Gregor Mendel observed nine different traits among his pea plants and found that certain traits, such as pod color, bred true only when two recessive alleles were present.Full Answer >
The terms "dominant" and "recessive" are used to describe the phenotypic expression of certain traits or characteristics an individual possesses and not the genes themselves. In humans, each gene has two copies, or alleles. A person with a dominant allele for a specific trait always expresses that trait, even if the other copy of the allele he possesses is recessive. Dominant alleles repress, or mask, recessive alleles.Full Answer >