The organism can be classified into the domain Archaea.
The scientist isolated a single celled organism from the bottom of a sulfur hot spring and when examined under the microscope, the cell was very small and had no nucleus. Archaea are the organisms which live in extreme conditions and are called the extremophiles. They can tolerate high temperatures and survive in hot springs, anaerobic conditions and are acid-tolerant. The cells are very small and are similar to bacteria in lacking a nucleus and membrane bound organelles. The cell membrane is bound by a cell wall. They reproduce by binary fission, fragmentation or budding.