Question

homework - evidence of evolution
fossil records indicate that earth was first inhabited by bacteria - like organisms. these organisms
o were single - celled
o had organ systems
o were multi - cellular
o had a nucleus

Explanation:

Bacteria - like organisms are prokaryotes. Prokaryotes are single - celled. Organ systems are found in complex multicellular organisms. Multicellularity came much later in evolution. Prokaryotes (bacteria - like organisms) do not have a nucleus.

Answer:

were single - celled