Polygenic Inheritance PDF
Document Details
Uploaded by CommendableSard7063
Loyola College
Tags
Summary
This document explains polygenic inheritance, highlighting how multiple genes influence a single trait. Examples provided include skin color and wheat kernel color, illustrating the concept of multiple alleles affecting the phenotype. This document also includes the phenotypic ratio for polygenic inheritance, 1:4:6:4:1.
Full Transcript
POLYGENIC INHERITANCE When one phenotypic character is controlled by more than one gene , it is called polygenic inheritance. Kolerenter is known as father of polygenic inheritance. It is also called quantitative inheritance. The quantity of inheritance depends on dominant alleles. Do...
POLYGENIC INHERITANCE When one phenotypic character is controlled by more than one gene , it is called polygenic inheritance. Kolerenter is known as father of polygenic inheritance. It is also called quantitative inheritance. The quantity of inheritance depends on dominant alleles. Dominant alleles have cumulative or additive effect each expressing part of trait. Genes involved in quantitative inheritance is known as polygenes. Eg. Skin colour of man, wheat kernel colour Skin colour in man was first studied by Devenport (1913) in Negro-Europeian inter marriage. Skin colour is due to pigment melanin. More pigment , darker in colour. There are 3 genes (polygenes) controlling the production of melanin pigment. For our convenience we consider only two pair of genes For Negro AABB For Albino aabb Example:2 Wheat Kernal Colour Example:2 Wheat Kernal Colour Dark red White X 4 dominant genes: Dark red 3 dominant genes: Red 2 dominant genes: medium red 1 dominant gene: light red No dominant gene: white The phenotypic Ratio of polygenic inheritance: 1:4:6:4:1 Thank you
