Bacteria evolved from LUCA about 3.5 billion years ago. They take a number of forms, but their internal structure is pretty uniform. Some have flagella, allowing them some individual mobility, but some do not have this feature. They have been found to communicate among themselves through simple chemical signals.
The little orange dots are Ribosomes, without which a bacterium could not be a living cell. For the important function of Ribosomes see our page for Eukaryots. Drawing of typical bacteria by Ali Zifan distributed under license Creative Commons Attribution-ShareAlike v4.0 International.
More on the origin of Plants and
Animals.