Human features like height, eye color, and hair color come in lots of slightly different forms because they are controlled by many genes, each of which contributes some amount to the overall phenotype.
Why do phenotypes for polygenic traits have so many variations?
Because multiple genes are involved, polygenic traits do not follow Mendel’s pattern of inheritance. Instead of being measured discretely, they are often represented as a range of continuous variation. Some examples of polygenic traits are height, skin color, eye color, and hair color.
Why polygenic inheritance can produce a greater variety of phenotypes for a trait?
Because polygenic inheritance traits are controlled by two or more genes, more allele combinations are possible, resulting in a greater range of phenotypes.
What determines phenotype in polygenic inheritance?
Polygenic inheritance is also involved in quantitative traits, in which multiple gene loci each contribute in a similar way to the phenotype so that the total number of contributing alleles determines the phenotype. In humans, height, weight, and skin color are examples of quantitative traits.
How many genes does polygenic inheritance have?
Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight.
How many phenotypes are in a polygenic trait?
A polygenic trait is one whose phenotype is influenced by more than one gene.
Why does a polygenic inheritance show a normal distribution among a population?
In the case of polygenic inheritance: Increasing the number of loci responsible for a particular trait increases the number of possible phenotypes. This results in a phenotypic distribution that follows a Gaussian (bell-shaped) normal distribution curve.
How can the same genotype result in multiple phenotypes?
However, when the same genotype is subjected to different environments, it can produce a wide range of phenotypes. These phenotypic variations are attributable to the effect of the environment on the expression and function of genes influencing the trait.
How does polygenic inheritance differ from Mendelian inheritance?
How does polygenic inheritance differ from Mendelian inheritance? Polygenic inheritance is the inheritance pattern of a trait that is controlled by two or more alleles. Mendelian inheritance are dominant traits. What things can influence gene expression?
What information can be obtained from a punnet square?
A Punnett square is a chart that allows you to determine the expected percentages of different genotypes in the offspring of two parents. A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes.
When more than one phenotype is influenced by the same gene then dominance?
“Dominance is not an autonomous feature of a gene in case more than one phenotype is influence by the same gene.” Dominance is not an autonomous feature of a gene in case more than one phenotype is influence by the same gene.
What produces an intermediate phenotype?
This intermediate phenotype is a demonstration of partial or incomplete dominance. When partial dominance occurs, a range of phenotypes is usually observed among the offspring. Although the offspring may show a variety of phenotypes, each one will lie along a continuum bracketed by the homozygous parental phenotypes.
Why are Polygenes called additive?
Polygenic Traits are Additive
Most traits are polygenic, meaning more than one gene contributes to their phenotypes. In this case, an individual inherits multiple copies of each allele, rather than inheriting one copy of each allele, from each parent. So, when a trait is polygenic, the alleles are additive.
What term describes phenotypic features that are coded for by several genes?
what term describes phenotypic features that are coded for by several genes, such as eye color in humans. – linked. – codominant. – polygenic.
Which of the following phenotypes is an example of polygenic inheritance?
Polygenic traits have many possible phenotypes (physical characteristics) that are determined by interactions among several alleles. Examples of polygenic inheritance in humans include traits such as skin color, eye color, hair color, body shape, height, and weight.
Why polygenic inheritance is called quantitative inheritance?
“Polygenic inheritance is defined as quantitative inheritance, where multiple independent genes have an additive or similar effect on a single quantitative trait.” Polygenic inheritance is also known as multiple gene inheritance or multiple factor inheritance.