<span>The smell of Danger.
Researchers have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. This is the first time that scientists have identified a chemical tag that would let rodents sense carnivores in general from a safe distance.</span>
C. one celled
because like animals they can move and are hetrotrauphs
They teach us what happened in Earth before we arrived. For example, if we had never found any dinosaur fossils, we would have no idea what happened. Fossils show us ancient life and what it was like back then.
Please give me brainliest ^.^
Answer:
a. repressor
b. regulator
c. operator
Explanation:
All constituent genes of an operon are transcribed in a coordinated manner, such as polycistronic mRNA, that is, multigenic, which is sequentially translated into proteins by ribosomes. The initiation of transcription can be regulated positively or negatively. The genes under negative control are constantly expressed unless they are "disconnected" by a repressor protein that will prevent gene expression by binding to a specific DNA sequence called operator, preventing RNA polymerase from initiating transcription in the promoter.
Those genes whose expression is under positive control will not be transcribed unless an activating protein is present which binds to a specific DNA sequence and helps RNA polymerase in the initial steps of transcription.
