A prokaryote is a single celled organism that is lacking a nucleus, mitochondria, and other membrane bound organelles. So determining the phylogenetic relationships among the present-day domains of life, the Archaea, Bacteria, and Eukaryote, has been of central importance to the study of early cellular evolution. Primordial Earth was a harsh environment however two of the main domains of prokaryotes were able to form. Archaea and Bacteria have a few differences with respect to DNA transcription, translation, and replication. Apart from that however they are very similar. Bacteria are the more complex organism of the two and were eventually were put to further use in the evolutionary path of the eukaryotic cell.
The theorized course by which prokaryotes paved the way to the first eukaryotic cells is known as endosymbiosis. The Endosymbiosis theory attempts to explain the origins of eukaryotic cell organelles such as mitochondria in animals and fungi and chloroplasts in plants. Endo means “within” and symbiosis is a type of “cooperation”. An early primitive heterotrophic prokaryotic cell engulfed an ancient auto-trophic bacterium and used its function to facilitate the creation of energy for the host cell. And thus the first eukaryotic cell was born. This eukaryotic cell first lost its cell wall and then the membrane of the cell eventually folded in on itself and