Search results
Results from the WOW.Com Content Network
Under the Polygenic Model, for traits, like height, to be continuous in a population there must be many genes that code for the trait. Otherwise, the expression of the trait is limited by the number of possible combinations of alleles. The many genes which code for the continuous trait are also further modified by environmental conditions. [3]
Mendelian traits behave according to the model of monogenic or simple gene inheritance in which one gene corresponds to one trait. Discrete traits (as opposed to continuously varying traits such as height) with simple Mendelian inheritance patterns are relatively rare in nature, and many of the clearest examples in humans cause disorders.
Gene expression plays a crucial role in determining the phenotypes of organisms. The level of gene expression can affect the phenotype of an organism. For example, if a gene that codes for a particular enzyme is expressed at high levels, the organism may produce more of that enzyme and exhibit a particular trait as a result. On the other hand ...
The genotype is commonly mixed up with the phenotype which describes the result of both the genetic and the environmental factors giving the observed expression (e.g. blue eyes, hair color, or various hereditary diseases). A simple example to illustrate genotype as distinct from phenotype is the flower colour in pea plants (see Gregor Mendel).
Autosomal traits are associated with a single gene on an autosome (non-sex chromosome)—they are called "dominant" because a single copy—inherited from either parent—is enough to cause this trait to appear. This often means that one of the parents must also have the same trait, unless it has arisen due to an unlikely new mutation.
One example of oligogenic inheritance is a case where one gene is sufficient to cause a trait, however its penetrance or expressivity is influenced by another gene, called a modifier. An example of such a case is the gene TGFB1 which modified a person's risk of developing Alzheimer's disease if they are carrying the disease variant of the gene ...
For example, having eye color is a character of an organism, while blue, brown and hazel versions of eye color are traits. The term trait is generally used in genetics , often to describe phenotypic expression of different combinations of alleles in different individual organisms within a single population , such as the famous purple vs. white ...
Monoallelic gene expression (MAE) is the phenomenon of the gene expression, when only one of the two gene copies is actively expressed (transcribed), while the other is silent. [ 1 ] [ 2 ] [ 3 ] Diploid organisms bear two homologous copies of each chromosome (one from each parent), a gene can be expressed from both chromosomes (biallelic ...