10.3.1 Define polygenic inheritance.
10.3.2 Explain that polygenic inheritance can contribute to continuous variation using two examples, one of which must be human skin colour.
(pol-ee-jen-ik) [Gk. polus, many + genos, race, descent]
An additive effect of two or more gene loci on a single phenotypic character.
polygenic inheritance Occurs when a trait is controlled by several gene pairs; usually results in continuous variation. PICTURE ...
A polygenic trait is due to more than one gene locus. It involves active and inactive alleles.
Active alleles function additively.
polygenic inheritance the condition in which some characteristics are determined by an interaction of genes on several chromosomes or at several places on one chromosome; one example is human skin color.
polymerase chain reaction see PCR.
- A continuous, rather than discrete, set of traits that are influenced by many genes.
Prolactin - A peptide hormone that induces lactation and parental care.
Polygenic inheritance is a pattern responsible for many features that seem simple on the surface. Many traits such as height, shape, weight, color, and metabolic rate are governed by the cumulative effects of many genes.
. Inheritance of traits influenced by multiple alleles; traits show continuous variation between extremes; offspring are usually intermediate between the two parents; also known as blending and quantitative inheritance.
On the other hand, polygenic inheritance, epistasis , gene interaction, operons, and regulatory circuits all involve a many-to-one relationship between genotype and phenotype.
Quantitative variation is usually due to in which the additive effects of two or more genes influence a single phenotypic character.
Dominance relationship Â- Epistasis Â- Polygenic inheritance Â- Pleiotropy Â- Plasticity Â- Canalisation Â- Fitness landscape
Epigenetics Â- Maternal effect Â- Dual inheritance theory
Developmental architecture ...
See also: Polygenic, Inheritance, Theory, Trans, Gene