Bad question. We don't know.
The oldest fossils we have are stromatolites, which look like modern cyanobacterial mats.
In the six-kingdom scheme, cyanobactera are classified under Eubacteria.
If your teacher tries to tell you that Archaebacteria came first, ask her for evidence. I don't buy the "traces of lipid found in ancient shale" argument. Too much possibility of contamination over the past several billion years -- and such lipids may have been formed through nonbiological processes on the early Earth.
The oldest fossils we have are stromatolites, which look like modern cyanobacterial mats.
In the six-kingdom scheme, cyanobactera are classified under Eubacteria.
If your teacher tries to tell you that Archaebacteria came first, ask her for evidence. I don't buy the "traces of lipid found in ancient shale" argument. Too much possibility of contamination over the past several billion years -- and such lipids may have been formed through nonbiological processes on the early Earth.