Multifactorial /Polygenic Traits. STUDY. Flashcards. Learn. Write. Spell. Test. PLAY. Match. Gravity. Created by. TLBarr3. Terms in this set (17) Polygenic inheritance. involves the inheritance and expression of a phenotype being determined by many genes, with each gene exerting a small additive effect.
Multifactorial inheritance refers to polygenic inheritance that also includes interactions with the environment. Unlike monogenic traits, polygenic traits do not follow patterns of Mendelian inheritance (discrete categories). Instead, their phenotypes typically vary along a continuous gradient depicted by a bell curve.
The inheritance of polygenic traits does not show the phenotypic ratios characteristic of Mendelian inheritance, though each of the genes contributing to the trait is inherited as described by Gregor Mendel. Many polygenic traits are also influenced by the environment and are called multifactorial.
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.
Traits that are controlled by multiple genes and/or influenced by the environment. Penetrance and expressivity. Traits that are controlled by multiple genes and/or influenced by the environment. Penetrance and expressivity. If you're seeing this message, it means we're having trouble loading external resources on our website.
CHAPTER 9 Polygenic and Multifactorial Inheritance. Many disorders demonstrate familial clustering that does not conform to any recognized pattern of Mendelian inheritance. Examples include several of the most common congenital malformations and many common acquired diseases ().These conditions show a definite familial tendency, but the incidence in close relatives of affected individuals is ...
Common medical problems such as heart disease, type 2 diabetes, and obesity do not have a single genetic cause—they are likely associated with the effects of multiple genes (polygenic) in combination with lifestyle and environmental factors. Conditions caused by many contributing factors are called complex or multifactorial disorders.
Multifactorial traits Several human characteristics show a continuous distribution in the general population, which closely resembles a normal distribution. This takes the form of a symmetrical bell-shaped curve distributed evenly about a mean. Polygenic / Multifactorial traits A normal distribution (Gaussian or bell shaped curve) is generated ...
Important concept in the multifactorial genetic disorders is the quantitative trait locus, which is used to map polygenic traits measurable in some quantitative manner.
Polygenic traits are much more complex than Mendelian traits. Rather than being shaped by a single gene alone, a polygenic trait is influenced by multiple genes. In humans, eye color and skin color are two of the most well-known examples. There isn't a single gene for darker brown or lighter white skin; rather, there are multiple genes, and the ...