The following points highlight the top three characters which are not heritable among animals. The characters are: 1. Acquired Modifications due to Disease 2. Characters Peculiar to Sex 3. Certain Parental Characteristics. Character # 1. Acquired Modifications due to Disease: Acquired modifications due to disease mutilation, use or disuse of parts, and changes due to the direct action of the [...]
In this article we will discuss about the role of environment in changing the form and degree of expression of some genes resulting in a corresponding change in the phenotype. Penetrance and Expressivity: The presence of a gene does not always bear an absolute relationship with the appearance or absence of a trait. In the ABO blood group system, the [...]
In this article we will discuss about:- 1. Definition of Epistasis 2. Types of Epistasis 3. Epistasis in Drosophila 4. Epistasis and Blood Groups in Man. Definition of Epistasis: Due to the phenomenon of dominance a recessive allele remains obscure in the hybrid. But when two different genes which are not alleles, both affect the same character in such a [...]