Name Date

AP: CHAPTER 25

THE HISTORY OF LIFE ON EARTH

1. Start with the origin of the earth and identify the time frame, conditions, and evidence for each of the following steps leading to current life forms on earth.

a. Origin of the earth

b. Prokaryotes

c. Oxidizing atmosphere

d. Eukaryotic cells

e. Multicellular life

2. What was significant about the discovery of the iron oxide bands in the sedimentary layers?

3. Describe the theory of endosymbiosis.

4. Why did evolution seem to slow 750 to 570 million years ago?

5. What was special about the Cambrium Explosion?

6. Describe a few adaptations essential for the invasion of plants onto land.

7. Describe the hypothesized conditions on earth when life arose.

8. List the four stages for the formation of life.

a.

b.

c.

d.

9. What metabolic processes would you expect to see in protobionts?

10. Why is RNA now thought to be the first genetic code?

11. What did Oparin, Haldane, Miller and Urey accomplish?

12. What are some of the possible locations for the first life forms?

13. Place the following metabolic processes in an order that fits the hypothesis for the origin of life: Photosynthesis, Aerobic Respiration, Fermentation, Nucleic Acid replication (RNA or DNA), Membrane transport.

14. What is meant by a reducing atmosphere?

15. Outline some valid arguments countering the reducing atmosphere hypothesis?

16. Explain the significance of the Miller-Urey experiment in testing the abiotic hypothesis.

17. Explain what protobionts are.

18. What discovery provides evidence that RNA was the first genetic material?

19. What is the proper sequence for the order of events in the evolution of a self-replicating system, assuming

that RNA was the first genetic material?

a. Replication of RNA

b. Reverse transcription of RNA

c. RNA à proteins

d. DNA à RNA à proteins

20. Describe the process of radiometric dating.

21. Give and example of how direct radiometric dating is used to date fossils and explain the process.

22. What is the downfall of this method & why?

23. Briefly explain the difference between prokaryotes and eukaryotes.

24. Briefly describe the hypothesis for the origin of mitochondria and plastids.

25. How does continental drift affect the evolution of life?

26. What are the 2 most known mass extinction events, when did they occur, what caused them, and what affect did they have on the environment?

27. What factors promote adaptive radiation?

28. For each of the factors promoting adaptive radiation, give an example of an organism that were formed as a result.

29. How can heterochrony cause the evolution of different body forms?

30. Why is it likely that Hox genes have played a major role in the evolution of novel morphological forms?

31. How can the Darwinian concept of descent with modification explain the evolution of such complex structures as the vertebrate eye?

32. Label the diagram to explain the Miller and Urey experiment to test the Abiotic Synthesis hypothesis.

33. Label the diagram to indicate the major events, the time frame, and the geologic eras of the

origin of life on Earth.

1