The correct genotypes of the parents are <span>AaBb and Aabb
In a cross of these two genotypes presented in the image below, 5/8 of the offspring would be deaf.
The individuals marked with a red square would be deaf because of the recessive aa alleles and the rest of the progeny that is marked with green would be deaf because of the presence of the B dominant allele.</span>
Answer:
Silencer
Explanation:
Silencers are the position and orientation free sequences that are present outside the protein-coding sequence of a gene. Silencers serve as a binding site for some transcriptional regulatory proteins that tend to inhibit gene expression. Binding of these "repressor" proteins to the silencers inhibits the gene expression.
The deletion of silencers from DNA would increase the rate of the gene expression as the inhibitory transcription regulatory proteins do not have binding sites to inhibit the gene expression. Therefore, the deletion of silencer sequences of the beta-globin gene would have caused the increased rate of its expression.