Forty years ago, living things were classified as Plant and Animal. Subsequently, living things belonged to either Eukaryotes or Prokaryotes. Eukaryotic organisms are those that have a distinct nucleus and the genetic material is within this distinct nucleus. That includes everything from fungi to palm trees to human beings and elephants as well as all plants, including even single-celled plants like the diatoms. In the more primitive prokaryotic organisms, the genetic material is scattered throughout the cell rather than in the nucleus.
Examples are bacteria and blue-green algae.
In the archaea, the genetic material is distributed in a linked ring in the cell. Furthermore, much of the genetic material in the archaea is different from anything known before in either bacteria or higher forms of life. There are several space missions being planned to the Red Planet. Those missions offer tremendous promise. Properly designed experiments may make it possible to detect living or fossil microbes on Mars.