Fossil Practice

Name:__________________________  Fossils: Practice what you know 1. What is a fossil? ……………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. ……………………….. ………………………………………………………………………………………………………………………………… ………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………… 2. What is Relative Dating? ……………………………………………………………………………………….………………………………….………………. ………………………………………………………………………………………………………………………………… ………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………… 3. What is an Index Fossil? …………………………………………………… ………………………………………………………………………………………………………………………………… ……………………………………………………………………………………….. ………….. ………………………………………………………………………………………………………………………………… ………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………… 4. To be useful as an index fossil, a species must have existed for a a. long long period period over over a wide wide geog geograp raphic hic rang range. e. b. long period period over over a small small geograph geographic ic rang range. e. c. short short perio period d over over a wide wide geogr geograph aphic ic range range.. d. short period period over over a small small geogr geographi aphicc range. range. 5. While looking for fossils fossils on an eroded hillside, hillside, you discover discover fossil coral and fish in one layer. In a layer layer just above, you find the fossil imprint of a fern frond and some fossil moss. Assuming the the rock has not been disturbed, disturbed, which of the following is the most probable conclusion? a. The The area area had been been a sea sea until until rec recent ent time times. s. b. A forest forest had had once grown grown there there but but had becom become e submerge submerged d by water. water. c. A sea sea had had been been replaced replaced by land land in ancie ancient nt times. times. d. A saltwate saltwaterr sea had had changed changed to to a freshwate freshwaterr lake in ancie ancient nt times. times. 6. Based on the fossil fossil record shown in this this figure, explain explain what has happened to the type of habitat found in the area as time passed. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ………………………………………………………………………………………………..

7. Which two techniques techniques that could be used to determine the age age of fossil A. ……………………………………………………….…………………………………………………………… ………………………………………………… …….…………………………………………………………………………………………………………………………………….. ……………………………………………………………………….. 8. The diagram shows shows undisturbed sedimentary sedimentary rock strata containing containing fossils. Which statement statement best summarizes summarizes the history of this this area? a. The area area was was once a forest forest and and was repla replaced ced by a freshwa freshwater ter lake lake b. The area area was was once a freshwat freshwater er lake lake and was repla replaced ced by by a saltwater sea c. The area area was was once a saltwate saltwaterr sea and and later later was replaced replaced by a coniferous forest d. The area area was was once a saltwate saltwaterr sea and and later later was replaced replaced by a forest

9. What are isotopes? ………………………………………………………..…………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………………………………………………………… 10. What is Radioactive Dating? ………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………………………………………………………… 11. What is half-life? ………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………………………………………………………… 12. How long is the half-life of potassium-40? ……………………………………………………………………………………………..…………… 13. Based on this graph, what is the approximate half-life of carbon-14. …………………………………………………………………………. 14. A fossil bone was found to contain about one sixteenth (1/16) of the amount of carbon-14 that was originally present. What is the approximate age of the bone ………………………………………..…………………………………….

15. The age of Earth is estimated at about ……………………………………………………………………………………………………………… 16. The first living organisms on Earth were …………………………………………………………………………….…………………………………… 17. The oldest fossils known are 3.8 billion years old and were ………………………………….…………………………………………. 18. When did the production of oxygen by photosynthetic bacteria begin? …………………………………………………..

19. What major evolutionary event occurred at the point on the graph indicated by X? ……………………………………………………………………………………………….. ………………………………………………………………………………………………..

20. What do you think happened at point Z? ………………………………………………………………………………………………….. ………………………………………………………………………………………………….

21. According to this figure, what was earliest form of multicellular life on Earth? a. fish b. Invertebrates like jelly fishes and sponges c. land plants d. reptiles

22. The picture shows three columns of exposed rock that are within a three-kilometer area. According to this information, the dominant past environment of this area was a. Artic tundra b. Shallow marine c. Deciduous forest d. Tropical desert

23. In which type of environment did this fossilized fish most likely live? a. Deep ocean trench b. A coral reef c. A freshwater lake d. Near an ocean vent

the

Use the Geologic Time Scale on next page to answer these questions. 1. Based on the fossil evidence, when did life first evolved on Earth? ………………………………………………….…… 2. During what Period did the first vertebrates evolved? ………….………..…….……………………………………..……………. How long ago was this? ………………………………………………………………………………….…… What type of vertebrates were these animals? …………………………………………………………………..… 3. During what Period did the first plants evolved? ………….………..………………………………………………………………… How long ago was this? ………………………………………………………………. 4. During what Period did the first dinosaurs evolved? ………….…………………………………………………………………… How long ago was this? …………………………………………………………………. 5. The dinosaurs and many other species became extinct in a relatively short period of time that marks what is known as the K-T boundary. The K-T boundary is the boundary between the Cretaceous and Tertiary periods . About how long ago did the dinosaurs become extinct? …………….…………………………………………………………… 6. Imagine that you found a fossil of a bird that dates to 230 million years ago. Why would this find be astonishing (surprising) to scientists?..………………………………..……………..……………………………..………………………………………… …………………………………………………………………..………………………………..………………………………………………………………………………………..…… 7. During what period were most coal deposits formed? …………………………………………………………………………………………… How long ago did this happen? ………………………………………………………. 8. What evolved first, land plants or land animals? …………………………………………….…………………………………………………………… 9. If you could go back in time, to the Ordovician and Cambrian Periods, where would you have to go to look for living organisms: land, freshwater, or oceans? Explain your answer. ……………………………………………..……………………… ……………………………………………………………………………………………………………………………………………………………………………………………………….. 10. During which period did humans evolve? ……………………………………………………………………………….………………………………………

Radioactive isotopes decay over time giving off radiation as they break down. Scientists compare the amount of the original radioactive element to the amount of the new element present, which has formed as a result of the decay.

Suppose that you start with 100 g of a certain radioisotope that decays to half its original amount in 50,000 years. a. Complete Table 1. Amount of Original Isotope

Amount of “Daughter” Material

 Years Passed

(decayed element)

100 grams

0 grams

0 50 000 100 000 150 000 200 000

3.125 grams

96.875 grams Table 1

b. Graph the data in Table 1 in order to show the relationship between the passage of time and the amount of original radioisotope.

250 000