Chapter+17+Questions+(phase+4)

Chapter 17 Questions 17-1 17-2
 * 1) Who was Edwin Hubble?
 * 2) Describe a red shift and a blue shift?
 * 3) What is the Big Bang theory? What evidence is there to support the Big Bang theory?
 * 1) Describe the early atmosphere. What types of gases were present? Which types of gases were not present? What evidence shows that certain gases were not present?

17-3
 * 1) Why would the Earth 4.6 billion years ago not be able to sustain modern life? What is present in today’s Earth that does help to sustain life?
 * 2) List and explain the popular explanations for how Earth became what it is today.

17-4
 * 1) What did Oparin and Haldane study?
 * 2) What is the heterotrophs hypothesis?
 * 3) What did Miller and Urey study?
 * 4) What did Cyril Ponnamperuma study?
 * 5) What did Cairns-Smith study?
 * 6) Describe the evidence for the three steps of the heterotrophs hypothesis.
 * 7) How does the discovery of catalytic RNA help to solve the chicken-and-egg problem in the origin of life?

17-5
 * 1) What did Carl Woese study?
 * 2) What are possibilities for the first life-forms? Give evidence for each.

17-6
 * 1) What are microfossils?
 * 2) What are stromatolites?
 * 3) Why has no one found fossils older than 3.485 billion years?
 * 4) What are methanogens?
 * 5) What does hydrothermal mean?
 * 6) What characteristics make methanogens and related bacteria good candidates for being the first organisms?

17-7
 * 1) What is symbiosis?
 * 2) What are endosymbionts?
 * 3) What is the endosymbiont hypothesis?
 * 4) What evidence supports the idea that mitochondria and plastids originated from free-living prokaryotes?