Ch 14 Bio Genesis

Chapter 14: Biogenesis Biogenesis: life coming from life Abiogenesis: life coming from non-life (spontaneous generation) • • •

1680’s: Redi disproves spontaneous generation using flies 1780’s: Spallazani disproves spontaneous generation using broth o People did not believe him. Why?  Vital Force 1850’s: Pasteur defeats spontaneous generation using a swan neck flask and broth o Left it out for one year, yet no bacteria grew o Allowed air (and vital force) to get into the flask but nothing grew o Other notable experiments: milk, wine, pox o “Father of Bacteria”

Early Signs of Life: • Earth (4.6 billion years ago (BYA)): o High Temperatures o Gas Cloud in Atmosphere o Heavy Elements to the Core o Lighter Elements to the Surface • Earth (3.8 BYA): o Cooler Temperatures o Water Formed o Atmosphere: Methane, Ammonia, Water, Hydrogen •

First • • • • •

1951: Dr. Miller and Dr. Urey (UC Berkeley) experimented o Used closed flask with earth’s first atmosphere + UV light + electrical spark o Produced urea + acetic acid + lactic acid + amino acid + ATP + DNA parts • All used or needed for life • Did not create life Cells: Prokaryotes, Bacteria Heterotrophic, Fossils date back 3.4 BYA Anaerobic, Fission Reproduction Probably RNA based Eukaryotes appeared with nucleus, cell organelles, sexual reproduction allowed evolution