19.3 Earth’s Early History – Flashcards

pink/orange

amino acids

Yes

Yes

Rise of oxygen in the atmosphere

yes

1. Water heated and water vapor forms 2. Mixture of methane, ammonia and hydrogen added to water vapor. 3. gases are bombarded by sparks of electricity 4. cold water condenses the gases causing droplets to form 5. after a week, liquid collected contains amino acids and other organic compounds

Inorganic matter --> simple organic molecules --> RNA nucleotides --> RNA able to replicate, synthesize proteins, and helps DNA function in information storage and retrieval

1. Microscopic fossils of prokaryotes resembling bacteria found in Archean rocks evolved in absence of oxygen 3.5 billion years ago 2. 2.2 billion years ago photosynthetic bacteria churned out oxygen which combines with iron in the oceans --> iron oxide, sank in the bottom of the ocean 3. oxygen accumulated in environment which drove early life forms to extinction and new life forms evolved with metabolic pathways using oxygen

lynn Margulis in 1960 noted that 1. Mitochondria and chloroplast contain DNA sismilar to bacterial DNA 2. mitochondria and chloroplast have ribosomes 3. They reproduce by binary fission when cells containing them divide by mitosis

sped up evolutionary change, and increases genetic variation