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9 Cards in this Set
- Front
- Back
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1. What is spontaneous generation? What was thought to be a vital element in this
process? |
Spontaneous generation is when Life comes from non-living material. Oxygen as a vital element. Common belief in ancient cultures: Flies from decaying meat and Mice from stored wheat.
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2. What is biogenesis?
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Biogenesis is that life can only come from living things.
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3. What experiment did Francis Redi perform that refuted spontaneous generation? How did Louis Pasteur take it further?
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In 1668 Redi places 2 sets of jars with: Decaying meat, both exposed to air. Difference: one was covered with gauze. Maggots only appeared to the non-covered set.
Pasteur fermentable a sugar solution in two glass flasks with a long swan neck. He boiled them to kill any present microorganisms. He broke the one flask for air to enter it. Microorganisms grew in broken flask only. |
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5. What is panspermia? What evidence is there for panspermia?
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Panspermia is Life on Earth originated elsewhere. Antarctic meteorite: From Mars, ALH84001, and Complex organic molecules.
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6. How was the environment of early earth different from today? Where would
organic molecules spontaneously assemble? |
Early Earth had no oxygen in atmosphere, very hot and had Extremophiles. Organic molecules would spontaneous assembly, Collected in oceans and they were the Building blocks or energy source.
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7. What is a heterotroph? An autotroph? What are two different classes of
autotroph? Which uses energy from sunlight and which uses energy from inorganic molecules? |
Heterotrophy
Consumes other organisms for food Autotroph Produces complex organic molecules from inorganic molecules Other sources of energy Photoautotrophs Photosynthesis via sunlight Chemoautotrophs Energy from chemical bonds in hydrogen sulfide, ammonium, etc. |
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8. What's the difference between an organic compound and an inorganic
compound? |
Organic Compound
Any molecule in which carbon is the primary element Hydrogen, oxygen Carbohydrates, proteins, alcohols, lipids Inorganic Compound Any molecule in which carbon is NOT the primary element Metals, alloys |
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9. What is the heterotroph hypothesis? Where would these initial organisms get
their chemical energy required for metabolism? |
Earliest life at least 3.5 billion ya
Fossil record Organic molecules collected in oceans Energy from volcanoes, UV, lightning Easily accessible Depletion required mutation to survive UV |
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10. What is the autotroph hypothesis? Where would these initial organisms have
gotten their energy? What are lithoautotrophs? Acidophiles? |
Chemoautotrophs
Extremophiles Energy from inorganic chemical reactions Types Lithoautotroph CO2 and rocks Acidophile pH < 3.0 |
