If you are wanting to know what that is in English, the answer is 'How do I intentionally vomit?' If you want to know how to do that, I guess stick your finger down your throat.
<em>The typical F2 ratio in cases of dominant epistasis is 12:3:1.</em>
<u>The epistasis is a form of gene interaction in which an allele in one locus interacts with and modifies the effects of alleles in another locus</u>. There are different types of epistasis depending on the type of alleles that are interacting. These include:
Dominant/simple epistasis: Here, a dominant allele on one locus suppresses the expression of both alleles on another locus irrespective of whether they are dominant or recessive. Instead of the Mendelian dihybrid F2 ratio of 9:3:3:1, what is obtained is 12:3:1. Examples of this type of gene interaction are found in seed coat color in barley, skin color in mice, etc.
Other types of epistasis include <em>recessive epistasis (9:3:4), dominant inhibitory epistasis (13:3), duplicate recessive epistasis (9:7), duplicate dominant epistasis (15:1), and polymeric gene interaction (9:6:1).</em>