User talk:মোঃ জিসান আহমেদ

A threshold trait is a trait, which is inherited quantitatively, but is expressed qualitatively. Normally a lot of genes form the basis of a threshold trait, which is why it should be treated as a quantitative trait.

A common characteristic of threshold traits and Mendelian traits is that they occur family wise.

When dealing with diseases with low population frequency it is not possible to differentiate between a Mendelian inherited disease and a threshold disease. In both cases the frequency of the disease will be much higher in close relatives of an affected animal, than the frequency in the population.

The distinction between the two forms of inheritance can only be based on test mating, in which the exact segregation ratio for Mendelian inherited diseases can be predicted. This is not the case for threshold diseases.