For questions 6-10:select from the choices below. Each letter can only be used O
ID: 88660 • Letter: F
Question
For questions 6-10:select from the choices below. Each letter can only be used Once. A. stromatolites B. carbon dioxide (CO_2) C. ^12C/^13C isotope ratios D. diatomic oxygen (O_2) E. hopanoids 6. A durable molecule that can serve as a signature for early life 7. First fossil evidence of life 8. Abundant now but not in the atmosphere of early earth 9. Substrate used for the biosynthesis of biomolecules by photoautotrophs 10. Provides evidence for life during the Archaean era without the necessity of determining molecular identity.Explanation / Answer
6-a durable molecules that can serve as biosignature for early life is CO2 produced from chemical potential gradients of aqueous and ionic hydrogen.
7-first fossil evidence of life occurred in form of Cyanobacterial hopanoids appear at 2.5 Gyr ago.
8-diatomic oxygen O2 is abundant now but not the atmosphere of early earth as comes after the origin of cyanobacteria during the Archean
9- Stromatolites are layered sheet-like sedimentary rocks created a chemical potential gradients of aqueous and ionic hydrogen, thus can be presumed to support the biosynthesis of biomolecules.
10- C12/C13 ratio provided evidence for the life during Archaean era without the necessity of determining molecular identity.