Archaea

The **archaea**, are a group of single-celled organisms that have no organelles or a nucleus. They are no longer classified in bacteria as a prokaryote, but as a separate category from both bacteria and eukaryota because of their unique differences in biochemistry compared to other forms of life. Although archaea’s physical similarities are more alike those of bacteria such as the size and shape, it is archaea’s genes and metabolic pathways that relate it more closely to eukaryotes. They have a dependence on ether lipids inside their cell membranes. Archaea have a wide variety of the sources of energy they use such as: sugars, ammonia, metal ions, or even hydrogen gas. They reproduce asexually through binary fission, fragmentation, or budding. They have also been known to live in very harsh environments such as salt lakes or hot springs, but were later found to inhabit soils, oceans, marshlands, and even the human colon. Archaea are very abundant in many places on the world and play a significant role in the carbon and nitrogen cycle.

Sulfolobus is an extremophile that is found in hot springs and thrives in acidic and sulphur-rich environments.

Halobacteria