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19.1 Origin of Life
  • A chemical evolution proceeded from monomers to polymers to protocells.
  • The primitive atmosphere contained no oxygen, and the first cell may have been an anaerobic fermenter.
  • The first cell was bounded by a membrane and contained a replication system; that is, DNA, RNA, and proteins.
  1. Briefly describe the experiment conducted by Stanley Miller in 1953 concerning the origins of organic molecules on the primitive earth.
    Answer
  2. What are hydrothermal vents and what might be their significance to the chemical evolution of earth?
    Answer
  3. Phospholipid molecules added to water form structures called _____________.
    Answer
  4. What is chemosynthesis?
    Answer
 Essential Study Partner Summaries of major points:
  1. Chemical evolution is the increase in complexity of chemicals leading to the first cells
  2. The atmosphere forms
  3. Monomers evolve
  4. Polymers evolve
  5. A protocell evolves
  6. A self-replication system evolves
Art Quizzes
19.2 History of Life
  • The fossil record allows us to trace the history of life, which is divided into the Precambrian, Paleozoic, Mesozoic, and Cenozoic eras.
  • The first fossils are of prokaryotes dated about 3.5 BYA. Prokaryotes diversified for about 2 billion years before the eukaryotic cell and then multicellular forms evolved during the Precambrian.
  • Fossils of complex marine multicellular invertebrates and vertebrates appeared during the Cambrian period of the Paleozoic era. During the Carboniferous period, swamp forests on land contained nonseed vascular plants, insects, and amphibians.
  • The Mesozoic era was the age of cycads and reptiles. Mammals and flowering plants evolved during the Cenozoic era.
  1. What is meant by the 'half-life' of carbon 14 and how can it be used to determine the age of a fossil?
    Answer
  2. What type of organism is found in the first identifiable fossils?
    Answer
  3. What did the formation of an ozone shield in Earth's upper atmosphere mean for the development of life on land?
    Answer
  4. What is the endosymbiotic hypothesis?
    Answer
  5. What is a molecular clock and how can it be used to determine the age of species?
    Answer
  6. What major adaptations allowed reptiles to invade the land?
    Answer
 Essential Study Partner Summaries of major points:
  1. Macroevolution is the large scale pattern of change taking place over very long time spans
  2. Fossils tell a story
  3. Relative dating of fossils
  4. Absolute dating of fossils
  5. The Precambrian
  6. The Paleozoic era
  7. The Mesozoic era
  8. The Cenozoic era
Animations
(To play the animation, lengthen the pop-up window until the control bar appears.) Animation Quizzes
19.3 Factors that Influence Evolution
  • The position of the continents changes over time because the earth's crust consists of moving plates.
  • Continental drift and meteorite impacts have contributed to several episodes of mass extinctions during the history of life.
  1. The movements of continents across the surface of the earth is known as _____________.
    Answer
  2. How can continental drift help explain relationships among organisms?
    Answer
 Essential Study Partner Summaries of major points:
  1. Continental drift
  2. Mass extinctions
Animations
(To play the animation, lengthen the pop-up window until the control bar appears.) Animation Quizzes





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