Dna is linked to all body functions because it is the genetic material which contains all the genetic information about our whole body.
Hope this helps
The allele which has light color appears to be altering transcription and that is why the corresponding mRNA is absent in zebrafish which is homozygous. The protein we can say were absent because mRNA which is being required for protein synthesis it was not present.
If the allele had altered translation, mRNA which is functional would have been present but in the same case, the protein will still be absent.
Answer:
I feel it's to easily differentiate the positive from the negative...... like in gram staining of bacteria, the colour tell us which bacteria is gram positive or gram negative...... I just feel that this is science and it is advisable to know what the opposite result of an experiment should look like.