103 Chapter Notes -Dissociation Constant, Phenotypic Trait, Chromosome
Document Summary
The phenomenon of two or more genes affecting the expression of each other in various ways in the development of a single character of an organism is known as gene interaction. Most of the characters of living organisms are controlled/ influenced/ governed by a collaboration of several different genes. Mendel and other workers assumed that characters are governed by single genes but later it was discovered that many characters are governed by two or more genes. Such genes affect the development of concerned characters in various ways; this lead to the modification of the typical dihybrid ratio (9:3:3:1) or trihybrid (27:9:9:9:3:3:3:1). In gene interaction, expression of one gene depends on expression (presence or absence) of another gene. Gene interactions can be classified as: allelic/ non epistatic gene interaction/ - the alleles of the same gene interact in such a way to produce the new character. This type of interaction gives the classical ratio of 3:1 or 9:3:3:1.
