Stromatolites Were Formed by ____

Q26: The first organisms were most probably _.<br>A)eukaryotic<br>B)multicellular<br>C)protozoans<br>D)prokaryotic<br>E)algae

Q27: What has been detected in meteorites that

Q28: Before DNA, _ likely served as the

Q29: Mitochondria arose from an endosymbiotic relationship between

Q30: The first O₂ producing organisms were probably

Q32: A rise in oxygen in Earth's air

Q33: While it is very difficult to find

Q34: Which process or element was present first?<br>A)aerobic

Q35: The prevalence of iron-sulfide cofactors in organisms

Q36: The earliest species known to reproduce sexually