Domains Bacteria and Archaea: A Fascinating Comparison

Archaea are prokaryotic unicellular organisms that is, they lack a well-defined nucleus. However, they have distinct chemical or molecular characteristics which differentiate them from bacteria. These organisms were originally discovered in extreme conditions such as hydrothermal vents. They can survive in a diverse range of high acidic, saline, and anaerobic environments. They are also termed as extremophiles.

On the other hand, bacteria are also prokaryotic unicellular organisms. They can inhabit any area including air, water, soil, decaying organisms, et cetera. However, they are usually not found in such extreme conditions in which archaea can survive.

For example, Pyrolobus fumarii can survive even at 113 °C temperature. Bacteria, on the other hand, are not able to survive in such extreme heat. This contrast in their ability to withstand extreme conditions is a key difference between the two domains.