Question

Why were Archaea and Bacteria grouped together by biologists until recently?

Answer 1

Archaea and Bacteria were grouped together because they were both Prokaryotes since they had no nucleus. Scientists then realized they were different because archaea can live in extreme environments, and bacteria can't.

hopefully my answer helps u 

Answer 2

Archaea and bacteria were kept together in fact they were classified as bacteria. They have some similarities in common.

• They were morphologically similar.

• They both were prokaryotes which means they were not compartmentalized.

• Archaea and bacteria had similar kind of eating habits.

• They both used similar ways of respiration which means they both were able to respire using oxygen and other substances too.