FOSSILS

1. FOSSILS UNIT ONE

2. WARM-UP #1 • How do most fossils form?

3. ANSWER • Living things die and their remains are covered by sediments.

4. WARM-UP #2 • A fossil formed when minerals replace all or part of an organism is called____________.

5. ANSWER • Petrified fossil

6. WARM-UP #3 • Which type of fossil can provide clues about the activities of ancient organisms?

7. ANSWER • Trace fossil

8. VOCABUALRY • Fossil • Mold & cast • Petrified

9. VOCABULARY • Fossil • A trace of an ancient organism that has been preserved in rock • Mold & cast • A fossil formed when an organism buried in sediment dissolves, leaving a hollow area

10. VOCABULARY • Petrified • A fossil in which minerals replace all or part of an organism

11. WARM-UP #4 • The fossil record shows that life on Earth has changed over time. For example, paleontologists have found that older rocks contain fossils of

12. ANSWER • organisms that are simpler than those alive today.

13. WARM-UP #5 • The relative age of a rock is

14. ANSWER • its age compared to the ages of other rocks.

15. WARM-UP #6 • The law of superposition states that, in horizontal layers of sedimentary rock, each layer is

16. ANSWER • older than the layer above it and younger than the layer below it.

17. VOCABUALRY • Carbon film • Trace • Paleontologist

18. VOCABUALRY • Carbon film • A type of fossil consisting of an extremely thin coating of carbon on rock • Trace • A type of fossil that provides evidence 0f the activities of the ancient organism

19. VOCABUALRY • Paleontologist • A scientist that studies fossils to learn about organisms that lived a long time ago

20. WARM-UP #7 • What is the age of an intrusion of igneous rock in relation to the sedimentary rock layers through which it passes?

21. ANSWER • always younger

22. WARM-UP #8 • The fossils of organisms that were widely distributed but only lived during a short period of time are called

23. ANSWER • index fossils.

24. WARM-UP #9 • Why are index fossils useful to geologists?

25. ANSWER • They tell the relative age of the rock in which they occur.

26. VOCABUALRY • Relative age • Absolute age • Law of superposition

27. VOCABUALRY • Relative age • The age of a rock compared to the ages of rock layers • Absolute age • The age of a rock given as the number of years since the rock formed

28. VOCABULARY • Law of superposition • The geologic principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it

29. WARM-UP #10 • The earliest life forms were

30. ANSWER • single-celled organisms.

31. WARM-UP #11 • What is a fossil?

32. ANSWER • the preserved remains or traces of an organism

33. WARM-UP #12 • In which type of fossil might you find the remains of an insect preserved with little or no change?

34. ANSWER • fossil in amber

35. VOCABUALRY • unconformity • Index fossil

36. VOCABUALRY • Unconformity • A place where old, eroded rock surface is in contact with a newer rock layer • Index fossil • Fossils distributed organisms that lived during only one short period

37. WARM-UP #13 • A type of organism that no longer exists on Earth is said to be __________.

38. ANSWER • extinct.

39. WARM-UP #14 • Fossils usually occur in _____________________ rock.

40. ANSWER • sedimentary

41. WARM-UP #15 • Generally, only the ________ parts of organisms become fossils.

42. ANSWER • hard

43. VOCABUALRY • Hydrocarbon • Petroleum

44. VOCABUALRY • Hydrocarbon • An energy-rich chemical compound that contains carbon and hydrogen atoms • petroleum • Liquid fossil fuel; oil

45. WARM-UP #16 • Footprints and trails are examples of__________________.

46. ANSWER • Trace fossils

47. WARM-UP #17 • The law of superposition helps geologists determine the________________ age of a rock layer.

48. ANSWER • relative

49. WARM-UP #18 • Rock layers are always _______________ than the faults that cut across them.

50. ANSWER • older