Chapter #6 Origins of Life on Earth.


1. Explain the concept of "panspermia"? Does this concept fully describe what the origins of life are? (page 93)

2. Do scientist understand the events that took our world from one with only pre-biological chemistry to one with life that operates under the use of RNA and DNA? If so explain these events, if not what events are missing? (page 93)

3. Provide a very brief and general definition that could serve to define what is living and what is not. (page 94)

4. Is fire alive? In what ways is it alive and in what ways is it not? (page 94)

5. Is a mule alive? In what ways is it alive and in what ways is it not? (page 94)

6. Is a virus alive? In what ways is it alive and in what ways is it not? (page 94)

7. What are the essential biogenic elements that act as the elemental building locks for terrestrial life? (page 96)

8. What are some of the possible organic molecular that could have served as the building blocks for more complicated molecules such as proteins and DNA, essential to the origins of life in the early Earth? (page 96)

9. The origins of life certainly required an energy source, is it more likely that the energy source was through chemical energy or from sunlight? Why? (page 96)

10. What are the three dominant processes that may have developed/brought organic molecules to the early Earth? (96-100)

11. Describe the apparatus design, operating theory and results of the Miller-Urey experiments. (page 96-97)

12. The requirement that the Early Earth's atmosphere had to have been reducing and contain Methane and Ammonia has a potential problem. Discuss this problem and how it eventually leads to an oxidizing atmosphere. (page 98)

13. Discuss the chemical pathways by which complex molecules may have been created in hydrothermal systems. (page 98-99)

14. What role may comets, asteroids and meteorites have played in the origin of complex molecules on the early Earth? (page 99-100)

15. Describe the "Chicken and Egg" dilemma that exists with trying to envision the origin for life having stemmed from having only the RNA molecule without the DNA molecule. How do ribozymes potentially resolve this dilemma? (page 102)

16. Are right-handed and left-handed molecules present in equal amounts in terrestrial living organisms? (page 105)

17. Which handedness do we find in sugars found in the backbone of RNA ad DNA molecules? (page 105)

18. Would the non-biological mechanisms that are thought to have produced the organic molecules that serve as the precursors to life excepted to produce an unequal amount of right-handed and left-handed molecules? (page 106)

19. Do the incoming organics that are brought to earth from meteorites and comets have the same abundance of left and right-handedness as terrestrial organics? (page 106)

20. What is the most general purpose of the cellular membrane? (page 106)

21. Describe how proteinoid microshperes and coacervates can be formed and how the formation of these structures shed light on the possible early formations of membranes. (page 107)

22. Where does Jakosky suggest as the most likely location for the earliest forms of life Earth? Why does this location seem to be most likely? (page 108)