What describes polygenic inheritance?
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.
What is the meaning of polygenic character?
A polygenic trait is one whose phenotype is influenced by more than one gene. Traits that display a continuous distribution, such as height or skin color, are polygenic. Many polygenic traits are also influenced by the environment and are called multifactorial.
Are polygenic traits dominant?
Polygenic traits do not exhibit complete dominance as do Mendelian traits, but exhibit incomplete dominance. In incomplete dominance, one allele does not completely dominate or mask another. The phenotype is a mixture of the phenotypes inherited from the parent alleles.
What is complete dominance in genetics?
In complete dominance, the effect of one allele in a heterozygous genotype completely masks the effect of the other. The allele that masks the other is said to be dominant to the latter, and the allele that is masked is said to be recessive to the former.
What is the example of incomplete dominance?
When one parent with straight hair and one with curly hair have a child with wavy hair, that’s an example of incomplete dominance. Eye color is often cited as an example of incomplete dominance.
What is complete dominance with example?
Complete dominance occurs when one allele – or “version” – of a gene completely masks another. Brown eyes, for example, is a trait that exhibits complete dominance: someone with a copy of the gene for brown eyes will always have brown eyes.
What are examples of epistasis?
An example of epistasis is the interaction between hair colour and baldness. A gene for total baldness would be epistatic to one for blond hair or red hair. The hair-colour genes are hypostatic to the baldness gene. The baldness phenotype supersedes genes for hair colour, and so the effects are non-additive.