UNIT IV Chapter 12 The History Of Life

1. UNIT IV Chapter 12 The History Of Life

2. UNIT 4: EVOLUTION Chapter 12: The History of Life I. The Fossil Record (12.1) A. Fossils can form in several ways

3. 1. Permineralization- minerals carried by water are deposited around or replace the hard structure Petrified wood

4. 2. Natural casts- form when flowing water removes all of original bones, leaving impression in sediment. Minerals fill in the mold Archaeopteryx

5. 3. Trace fossils- record activity of organism. Include nests, burrows, imprints of leaves, and footprints

6. 4. Amber-preserved fossils- organisms trapped in tree resin that hardens into amber

7. 5. Preserved remains- form when entire organism becomes encased in material such as ice, volcanic ash, or immersed in bogs.

8. B. Most fossils form in sedimentary rock 1. Most common fossils result from permineralization 2. Best environments for fossilization include wetlands, bogs, rivers, lakebeds, and floodplains

9. C. Only 1 percentage of living things become fossils Why are so few complete fossils discovered?

10. How to get into the fossil record Organism Dies Covered Destroyed Decomposed Fossilized Destroyed Destroyed Stays Buried DISCOVERED!

11. b. Determining Earth’s Age   1). Use decay of uranium to determine age (long half-life)   2). Earth’s age about 4.5 billion years

12.  II. The Geologic Time Scale (12.2)   A. Index fossils are another tool to determine the age of rock layers.

13. 1. Index fossils- organisms that existed only during specific spans of time over large geographic area 2. Estimate age of rock layers by fossils they contain

14. B. The geologic time scale organizes Earth’s history   1. Geologic time scale- representation of the history of Earth a. Organizes by major changes or events b. Uses evidence from fossil and geologic records

15. 2. Divided into three basic units of time a. Eras- lasts tens to hundreds of millions of years. 1). Separated by periods of mass extinction b. Periods- most common used units. Lasts tens of millions of years c. Epochs-smallest units

16. V. Radiation of Multicellular Life (12.5) A. One of most important transitions in history of life 1. First appeared during Paleozoic era (544 million years ago)

17. 2. Huge diversity of animal species evolved a. At first all life was found in ocean  b. Eventually life moved onto land c. Dead remains of organisms from this era changed into coal and petroleum

18. 3. Paleozoic Era ended with mass extinction

19. B. Reptiles radiated during the Mesozoic era. 1. Age of reptiles 2. First mammals appeared 3. Era ended with mass extinction caused by meteorite impact

21. C. Mammals radiated during the Cenozoic era

22. What proportion of all species that ever lived has become extinct? a. less than 1 percent b. approximate one-half c. more than 99 percent d. It is impossible to estimate.

23. What proportion of all species that ever lived has become extinct? a. less than 1 percent b. approximate one-half c. more than 99 percent d. It is impossible to estimate.

24. Most fossils form in a. peat bogs. b. tar pits. c. sedimentary rock. d. the sap of ancient trees.

25. Most fossils form in a. peat bogs. b. tar pits. c. sedimentary rock. d. the sap of ancient trees.

26. The length of time required for half of the radioactive atoms in a sample to decay is its a. half-life. b. relative date. c. radioactive date. d. none of the above

27. The length of time required for half of the radioactive atoms in a sample to decay is its a. half-life. b. relative date. c. radioactive date. d. none of the above

28. How would you date a sample of rock that you suspect as being one of the earliest on Earth? a. Use a radioactive isotope with a short half-life. b. Use a radioactive isotope with a long half-life. c. Use an index fossil. d. It is impossible to date very early rocks.

29. How would you date a sample of rock that you suspect as being one of the earliest on Earth? a. Use a radioactive isotope with a short half-life. b. Use a radioactive isotope with a long half-life. c. Use an index fossil. d. It is impossible to date very early rocks.

30. The levels of division of the geologic time scale, from smallest to largest are a. eras, periods, and epochs. b. epochs, periods, and eras. c. periods, eras, and epochs. d. periods, epochs, and eras.

31. The levels of division of the geologic time scale, from smallest to largest are a. eras, periods, and epochs. b. epochs, periods, and eras. c. periods, eras, and epochs. d. periods, epochs, and eras.

32. The Mesozoic is often called the Age of a. Invertebrates. b. Vertebrates. c. Dinosaurs. d. Mammals.

33. The Mesozoic is often called the Age of a. Invertebrates. b. Vertebrates. c. Dinosaurs. d. Mammals.

34. Earth's most recent era is the a. Paleozoic. b. Mesozoic. c. Cenozoic. d. Precambrian.

35. Earth's most recent era is the a. Paleozoic. b. Mesozoic. c. Cenozoic. d. Precambrian.

36. Why did oceans not exist on Earth nearly 4 billion years ago? a. No water was present. b. Water remained a gas because Earth was very hot. c. Water existed as ice because Earth was very cold. d. none of the above

37. Why did oceans not exist on Earth nearly 4 billion years ago? a. No water was present. b. Water remained a gas because Earth was very hot. c. Water existed as ice because Earth was very cold. d. none of the above

38. Miller and Urey's experiments attempted to simulate the conditions a. of Earth's early seas. b. of Earth's early atmosphere. c. of Earth before liquid water existed. d. deep inside Earth.

39. Miller and Urey's experiments attempted to simulate the conditions a. of Earth's early seas. b. of Earth's early atmosphere. c. of Earth before liquid water existed. d. deep inside Earth.

40. A necessary condition for the evolution of life on Earth was a. the existence of DNA. b. free oxygen. c. the formation of the ozone layer. d. liquid water.

41. A necessary condition for the evolution of life on Earth was a. the existence of DNA. b. free oxygen. c. the formation of the ozone layer. d. liquid water.

42. What do proteinoid microspheres have in common with cells? a. They can store and release energy. b. They contain DNA. c. They contain RNA. d. They are communities of organisms.

43. What do proteinoid microspheres have in common with cells? a. They can store and release energy. b. They contain DNA. c. They contain RNA. d. They are communities of organisms.

44. The endosymbiont theory proposes that eukaryotic cells arose from a. single prokaryotic cells. b. multicellular prokaryotes. c. communities of prokaryotes inside a larger cell. d. communities of eukaryotes inside a larger cell.

45. The endosymbiont theory proposes that eukaryotic cells arose from a. single prokaryotic cells. b. multicellular prokaryotes. c. communities of prokaryotes inside a larger cell. d. communities of eukaryotes inside a larger cell.

46. What was the response of various groups of early organisms when oxygen levels rose in the atmosphere? a. extinction b. a move into airless habitats c. the evolution of metabolic pathways that used oxygen for respiration d. all of the above

47. What was the response of various groups of early organisms when oxygen levels rose in the atmosphere? a. extinction b. a move into airless habitats c. the evolution of metabolic pathways that used oxygen for respiration d. all of the above

48. The first organisms were a. prokaryotes. b. eukaryotes. c. proteinoid microspheres. d. microfossils

49. The first organisms were a. prokaryotes. b. eukaryotes. c. proteinoid microspheres. d. microfossils

50. A very large mass extinction occurred at the end of the a. Precambrian. b. Cambrian Period. c. Paleozoic Era d. Quaternary Period.