The cells is a basic unit of what

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

According to these anatomical structures which two animals are probably most closely related

Prokaryotic and eukaryotic cells are different in many ways other than the presence or absence of a nucleus. if both archaebacteria and eubacteria are prokaryotic cells, then why are archaebacteria more closely related to eukaryotic cells than they are to eubacteria?