Polygenic traits also have dominant and recessive alleles, but so many genes play a role in an organism’s phenotype for these traits that the final result is the sum of many complex interactions. It can be hard or impossible to figure out one gene’s effect on a polygenic trait.
Polygenic traits are those traits that are controlled by more than one gene. Such traits may even be controlled by genes located on entirely different chromosomes. Human height, eye and hair color are examples of polygenic traits. Skin color is another polygenic trait for humans and a variety of other animals.
The ones that are controlled by many genes. There is some subjectivity on what is oligogenic, which is controlled by a small number of genes. 2 to 30 is about the ballpark you might see. Over 30 and pretty everyone will call it polygenic. That’s i...
Polygenic traits are quite different from the classical Mendelian trait in where we see that one gene controls one characteristic or one phenotype. Surprisingly, most traits in humans, and in fact most traits in most organisms, are polygenic. Mendelian traits, although we spend a lot of time talking about them, are really the exception.
A "polygene” or "multiple gene inheritance" is a member of a group of non-epistatic genes that interact additively to influence a phenotypic trait. The term "monozygous" is usually used to refer to a hypothetical gene as it is often difficult to characterise the effect of an individual gene from the effects of other genes and the environment on a particular phenotype.
Just like non-polygenic traits, polygenic traits also have recessive and dominant alleles. However, since several genes are involved in the phenotype, the final result is an amalgam of information which makes it difficult to impossible to tease out one gene’s impact on a polygenic trait.
A quantitative trait locus (QTL) is a region of DNA which is associated with a particular phenotypic trait, which varies in degree and which can be attributed to polygenic effects, i.e., the product of two or more genes, and their environment. These QTLs are often found on different chromosomes.The number of QTLs which explain variation in the phenotypic trait indicates the genetic ...
Polygenic inheritance is a type of incomplete dominance inheritance, where the expressed phenotypes are a mixture of inherited traits. Polygenic traits have a bell-shaped distribution in a population with most individuals inheriting various combinations of alleles and falling within the middle range of the curve for a particular trait. Examples ...
Mendelian traits in humans concerns how, in Mendelian inheritance, a child receiving a dominant allele from either parent will have the dominant form of the phenotypic trait or characteristic. Only those that received the recessive allele from both parents, known as zygosity, will have the recessive phenotype.Those that receive a dominant allele from one parent and a recessive allele from the ...
In summary, traits that are polygenic are controlled by two or more genes. The Swedish geneticist Nilsson-Ehle used wheat and kernel color to first explore the concept of polygenic inheritance.