Why is archaea prokaryotic?
A prokaryote is a cell which lacks membrane-bound nucleus, or any membrane-bound organelle.
There are two domains of prokaryotes, Archaea and Bacteria. Archaea is prokaryotic because it doesn't have a nucleus, nor any membrane-bound organelles. The reason why Archaea is different from Bacteria is it is more prominent, most of them are extremophiles. Archaea could stay alive in extreme conditions such as 113 °C (235 °F), at high pressure, or in concentrated acidic environments.