because you opened your hand
A nucleus would show that a cell is a eukaryote.
My answer will be the plate tectonic theory that explains a variety of geological features and events and that has to do with, among others, the expansion of the ocean floor.
Aristotle was the first scientist who attempted to divide organisms in group, he first divided then in animals and plants.
The animals were further classified as "with blood" and "without blood", being the with blood the humans and mammals, and egg-bearing animals. The "without blood" are the invertebrates, like insects, crustacea and mollusks.
The plants, for Aristotle, were sub
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.