Question

The first cells were most likely similar to what types of cells

Answer 1

They were most likely similar to prokaryotic cells. Prokaryotic cells are mostly bacteria cells that were first revealed in earlier times of earth. Prokaryotes and single-celled organisms are also the reason our world is the way it is today due to the supernova explosion around one-billion years ago that gave us the element of oxygen. Prokaryotes still exist to this very day, some whom are helpful bacteria, and others whom carry around viruses.

Answer 2

The first cells were most likely primitive prokaryotic-like cells, even more simplistic than these E. coli bacteria. The first cells were probably no more than organic compounds, such as a simplistic RNA, surrounded by a membrane.