It is possible for a repressor to negatively regulate the expression of an operon because: A. the repressor-binding site overlap
s the promoter site of the operon, allowing it to physically block the binding of RNA polymerase. B. the repressor induces the expression of the inducer by binding to the promoter that comes before the inducer gene. C. the repressor-binding site on the DNA overlaps with the translation start site, thereby preventing the transcription. D. one of the structural genes expressed in the operon negatively regulates the repressor. E. the repressor physically blocks where the activator should be binding on the operator region.
Essential amino acids cannot be made by the body. As a result, they must come from food. The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
<span>Basically, the breeder selects individuals with desired traits (high milk yields, lots of wool etc) and keeps breeding then until the descendants display a very exaggerated set of traits.
