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 ...
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.
Polygenic inheritance - A continuous, rather than discrete, set of traits that are influenced by many genes.
Prolactin - A peptide hormone that induces lactation and parental care.
Search images - Key stimuli used to find food and other resources.
~, also known as quantitative inheritance, is the gene interaction in which a given trait is conditioned by several different genes having alleles that may or may not contribute to increase the phenotype intensity.
~. 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, ~, epistasis , gene interaction, operons, and regulatory circuits all involve a many-to-one relationship between genotype and phenotype. Wheat color provides a good example of ~, the contribution of more than one gene to a single trait.
Quantitative variation is usually due to ~ in which the additive effects of two or more genes influence a single phenotypic character.
Discrete characters, such as flower color, are usually determined by a single locus with different alleles that produce distinct phenotypes.
Dominance relationship Â- Epistasis Â- ~ Â- Pleiotropy Â- Plasticity Â- Canalisation Â- Fitness landscape
Epigenetics Â- Maternal effect Â- Dual inheritance theory
Segmentation Â- Modularity
Evolution of genetic systems ...
See also: What is the meaning of Polygenic, Inheritance, Gene, Human, Trans?