Activators and repressors are transcription-control elements that are found in eukaryotic organisms. These elements function during the process of transcription, where a DNA molecule is coded onto a RNA molecule for it to be sent to ribosomes outside of the nucleus and then polypeptide chains are produced from it.
The activators and repressors control which proteins are made, which means that they can either hinder or promote certain functions in the cells of the body. Therefore, even though all of the cells have the same set of DNA, some are able to produce HCl, while others produce other substances such as insulin.
Because you would not want to change anything in your experiment you are just changing what you are observing
Answer:
a. to defend against bacteria
Explanation:The skin helps protect the body and various body cells from infection. A break in the continuity of a skin can result into harmful germs,bacteria infection penetrating into the body system. Hence the skin is a protective covering from germs,infection.
Most erosion is caused by winds breaking up rock