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Across 2. current period 5. the problem with the hypotheses involving liposomes, coacervates, and microspheres is that they were unable to do which process 8. Sidney Fox hypothesized that these structures formed when amino acids and cyanides were dripped onto clay 9. lasts several million years 10. CH4 12. era that consists of tertiary and quartenary periods 15. representation of Earth's history 19. an advantage of DNA to RNA, is that DNA is ______ 21. period in which amphibians, winged insects, and early conifers were present 23. adaptive radiation tend to follow these events 24. meteorites may have contained many of these molecules when they collided with Earth 25. first 700 million years of Earth's existance 29. membrane spheres made of lipid molecules 34. cloud of gas and dust in space 35. RNA molecules that can catalyze reactions 36. English geologist that discovered that certain rock layers contained fossils unlike those in other layers 37. period with diversification of insects, birds, fish, and flowering plants 38. period in which fish diversified, first sharks, forest arose, first ferns 39. period in which flying reptiles arose, fern and cycads were common, dinosaurs evolved 40. period in which first birds arose, oceans were full of fish and squid

Down 1. fossils that existed only during specific spans of time 3. last ten to hundreds of millions of years 4. diversification of one ancestral species into many descendent species 6. era that consists of ordovician and silurian periods 7. chemical that comes from ocean floor to form chimney like structures 11. vast majority of earth's history, origin of eukaryotes and cyanobacteria 13. Miller-Urey used this to represent lightning in their experiments 14. period in which dinosaurs peaked and then became extinct 16. these structures were formed by adding gum arabic to gelatin 17. the walls of the compartments in the chimney structures may have formed the first ____ 18. era that consists of triassic and cretaceous periods 20. period in which diverse marine invertebrates and the earliest vertebrates were common, massive glaciers formed 22. branch of science that studies life outside Earth 26. example of a perfect index fossil 27. period in which all existing animal phyla developed 28. Jeffrey Bada hypothesized that nucleotides may have formed in ice ____ 30. period in which Pangaea formed and modern pine trees were common 31. period in which earliest land plants arose, glaciers melted to form seas 32. NH3 33. last tens of millions of years