Evolution: Early Earth

Question 1

Miller-Urey Experiment

Answer 1

Simulated the conditions of Early Earth using chemical reactions. Provided evidence that early organic molecules actually came from inorganic molecules.

Question 2

Endosymbiotic Theory

Answer 2

Provided evidence that eukaryotic cell organelles (mitochondria and chloroplasts) were originally free-living photosynthetic bacteria. Absorbed into the cell through endocytosis. Formed the first plant cells.

Question 3

Evidence of endosymbiotic theory

Answer 3

Mitochondria and chloroplasts have their own DNA, which is circular and single-stranded. They are membrane-bound organelles and undergo cell division through binary-fission.

Question 4

Early Earth Atmosphere

Answer 4

Earth formed approximately 4.6 million billion years ago. Mixture of gases and solids. Had almost no atmosphere. Surface was molten and as it cooled, new gases emerged, including hydrogen sulfide, methane, CO2. Almost 200 times as much CO2 as we have today!

Question 5

Emergence Of Oxygen

Answer 5

Photosynthetic bacteria formed via endosymbiotic Theory. Changed Earth’s atmosphere by decreasing CO2 and increasing O2.