The Geologic Time Scale: Study Guide (Quiz Grade), Due Monday

The Geologic Time Scale: Study Guide (Quiz Grade), Due Monday Put the following items in order from oldest (1) to most recent (4) by writing a number in the blank beside each. ___1. Mesozoic Era ____ 2. Precambrian Time _____ 3. Cenozoic Era ___ 4. Paleozoic Era

5. Why is the geologic time scale used to show Earth’s history?

6. What methods did geologists use when they first developed the geologic time scale?

7. How did geologists decide where one division of the geologic time scale ends and the next begins?

Building Vocabulary Fill in the blank to complete each statement. 8. Geologists divide the time between Precambrian Time and the present into three long units of time called ______. 9. The record of life forms and geologic events in Earth’s history is called the ______.

10. According to the geologic time scale, sequence the following in order of evolution. Make #1 the most primitive life form. ______birds ______early mammals ______reptiles ______amphibians ______insects ______single-celled life forms ______fish ______flowering plants ______dinosaurs ______(more) modern humans ______humans ______early multi-celled life forms 12. Why are fossils important tools for understanding the history of life on Earth?

13. When is an organism considered extinct?

14. In the following list, circle the data about a long-dead organism that can be determined by fossils: weight size odor diet # offspring birthdate height disease history

15. What are index fossils and how are they used to determine the age of related strata?

16. If you found fossils of seashells in a rock layer near the top of a mountain, what would the fossils tell you about the history of that area? 17. Determine which time blocks the following events occurred. Write the name of the specific time block in the appropriate blank. All blanks will not be filled because some events are not broken down into the same time detail. . Description Eon Era Period Epoch Humans Rise of mammals Flowering plants Birds First dinosaurs/ mammals First reptiles First amphibian s First insects First fish Explosion of life forms Multi- celled organisms Single celled organisms 18. Fossils form in different ways. Identify the type of fossil being described in the list below. Place the name of the fossil type in the blank provided next to the description. ☺ Acids eat away the skeleton or shell and leave an impression in the rock → ______☺ This is formed when a mold fills with minerals → ______☺ Minerals in plant cells crystallize; minerals enter openings or cavities in shell or bones → ______☺ Whole organisms locked in tar pits, asphalt, amber, etc. → ______

19. Most fossils form in ______rock. The ______of fossils within this type of rock layers help scientists construct the geologic time scale.

20. Sequence the following events in the fossilization process: ______Over time, the surrounding material builds up and turns to rock. ______The rock above eventually erodes and the fossil is exposed. ______The remains are rapidly buried by sediment in streams. ______An animal dies and begins to decompose. 21. In the undisturbed rock strata illustrated below, indicate in which layer you will find the oldest and the youngest fossils. Write the terms “oldest” and “youngest” in the appropriate strata. ______A B C D

The most primitive fossils normally would be found in layer ______.

17. Which is more precise, absolute or relative dating? WHY?

18. . How is radioactive dating used to tell the age of rocks and fossils?

19. In reference to item #16 above, what scientific law is begin applied to determine the answer to the question?

20. What are three possible exceptions to the Law of Superposition? Draw each of them and indicate in each drawing the youngest and oldest layers.

21. Why are fossils important tools for understanding the history of life on Earth?

22. When is an organism considered extinct?

23. In the following list, circle the data about a long-dead organism that can be determined by fossils: weight size odor diet # offspring birthdate height disease history

24. What are index fossils and how are they used to determine the age of related strata?

25. If you found fossils of seashells in a rock layer near the top of a mountain, what would the fossils tell you about the history of that area?

16. How do ice cores allow scientists to determine Earth climate changes over time? (Hint: what two things about Earth can be determined from ice cores?) 18. When sudden, abrupt changes (or gradual changes, for that matter) occur within an organism’s habitat, one of three things must happen (the organism’s species must do one of three things). What?

19. What are two ways the extinction of an animal can affect the ecosystem in which it lives?

20. Scientists estimate that of all the species ever to exist on earth, ______% have become extinct.

21. The average species survives ______to ______million years. 22. List at least 8 events that can bring about the extinction of a species.

23. Answer the following questions about mass extinctions:

. what is a mass extinction?

. are they a common occurrence in Earth’s past?

. how many species can face extinction?

. where do scientists obtain evidence for them?

. what is a benefit?

. what is the most famous example?

. what is believed to have caused this particular example?

24. Is the rate of extinction of species on the Earth increasing or decreasing? List some possible reasons for this.

25. What is a fault?

26. The energy produced by earthquakes moves through the Earth in the form of ______. 27. Compare and contrast lava and magma: