The single characteristic that separates kingdoms Archaebacteria and Eubacteria from all other kingdoms is their lack of a membrane-bound nucleus and other membrane-bound organelles.

This means they are prokaryotic, unlike all other kingdoms, which are eukaryotic.

Here's a breakdown:

* Prokaryotes:

* Single-celled organisms

* Lack a nucleus and other membrane-bound organelles

* Genetic material (DNA) is located in a region called the nucleoid

* Examples: Bacteria and Archaea

* Eukaryotes:

* Single-celled or multicellular organisms

* Have a membrane-bound nucleus containing their DNA

* Possess other membrane-bound organelles, like mitochondria, endoplasmic reticulum, Golgi apparatus, etc.

* Examples: Protists, Fungi, Plants, Animals

So, while Archaebacteria and Eubacteria share many similarities, they are fundamentally different from all other kingdoms because of their prokaryotic nature.