1 / 9

EK 1D1

EK 1D1. There are several hypotheses about the natural origin of life on Earth, each with supporting scientific evidence.

davis-king
Download Presentation

EK 1D1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EK 1D1 There are several hypotheses about the natural origin of life on Earth, each with supporting scientific evidence

  2. Primitive Earth provided inorganic precursors from which organic molecules could have been synthesized due to the presence of available free energy and the absence of a significant quantity of oxygen

  3. Conditions on Early Earth • Earth was very hot, evaporating the liquid water into the atmosphere • As the earth cooled, gravity-trapped water vapor condensed • fell as rain • did not boil away but remained impounded in pools that became lakes and oceans • It was also believed that tectonic activity caused many volcanic eruptions at that time

  4. From present-day volcanoes, we know that when they erupt • Release carbon dioxide • Nitrogen • And a host of nonoxygengases • With no protecting atmosphere, the earth was constantly bombarded with • Meteorites • Other space debris still in circulation from the big bang

  5. From current astronomical research, we know that meteorites can carry • Ice and other compounds • Including carbon-based compounds • Researchers believe, therefore, that early Earth's atmosphere consisted of • water vapor, carbon dioxide, carbon monoxide • hydrogen, nitrogen • ammonia and methane

  6. How/When Oxygen Appeared The answer is tiny organisms known as cyanobacteria, or blue-green algae These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen In fact, all the plants on Earth incorporate symbiotic cyanobacteria (known as chloroplasts) to do their photosynthesis for them down to this day

  7. Cells evolved from the functional assembly of organic molecule Complex molecules may have coalesced inside a space surrounded by a lipid or protein “bubble” “Bubble” was Precursor of a cell membrane Here, reactions could proceed more rapidly.

  8. https://www.youtube.com/watch?v=63IoOLXmzKg

More Related