Chapter 19.1 Prokaryotes - Chapter 19 Prokaryotes Age of the Earth Radioactive dating shows earth to be approx During formation elements concentrated

Chapter 19.1 Prokaryotes - Chapter 19 Prokaryotes Age of...

This preview shows page 1 - 9 out of 28 pages.

Chapter 19: Prokaryotes
Age of the Earth Radioactive dating shows earth to be approx. __________ During formation… _______ elements concentrated toward surface heavy elements concentrated toward _________ Examples: Silicon = light, Iron = heavy
Early Earth At first, Earth was too hot for life, but it cooled over time First evidence of life dates back to _________
Early Earth The earth’s environment when life originated was very different than it is today Little or no ______________ in the atmosphere Atmosphere full of _______________-rich gases such as SH2, NH3, and CH4 Also contained carbon dioxide, carbon monoxide, & gaseous nitrogen Once cooled, it did have ________________
Origin of Life Life would have begun with formation of ____________ molecules Contain _______________ Found in living things Examples: proteins, carbohydrates, nucleic acids, lipids Simple organic molecules formed into chains of molecules
Is this even possible? Yes. As shown by a number of experiments Most famous example: Stanley Miller’s Experiment Conducted in 1953 Attempted to re-create environmental conditions he believed existed on early Earth Found that ______________ formed Believed life started in a “primordial __________” A theory that has been criticized
Other experiments Since Miller, several experiment performed Done with various ______________ Many different ___________ compounds have been produced Amino acids, fats, sugars, parts of nucleic acids
Where did life begin?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture