1.2 The Fossil Record Review

1. How do scientists use fossils to determine the relative ages of rock layers?

• by comparing all the fossils in one rock layer
• by comparing fossils in many different rock layers

2. Which of these answers best describes a fossil?

• organism from which other organisms are descended
• remains of a once-living organism found in layers of rock, ice, or amber

3. Sometimes a fossil is formed as a result of the movement of an organism in soft sediment. Which of these are two kinds of trace fossils?

• tracks and burrows
• shells and bones

4. The diagram shows a portion of a fossil record in sedimentary rock. Different rock layers and fossils are clearly visible. Which layer of rock is the oldest?

• layer B is the oldest
• layer D is the oldest

5. The fossil record provides evidence of evolution. Look at the series of illustrations. They show one way in which a fossil forms, providing a record of an organism. Which kind of fossil is being formed?

• cast
• frozen remains

6. Which property of fossils allows scientists to determine the relative ages of rock layers?

• Fossils show change over time as species evolve.
• Fossils can be analyzed to determine their exact age.

7. A team of geologists compared the rock layers found in Florida to those found in northwest Africa. They placed all of the rock layers from the two regions in order from youngest to oldest. What did the team make?

• A geologic column
• A topographic map

8. How does relative dating help determine the age of a fossil?

• It determines whether a fossil formed before or after another fossil.
• It gives us the exact date an organism lived.

9. Juan is studying fossils. His teacher wrote the following statements on the board and asked the students to put them in the correct order to describe how fossils are formed. 1. Layers of sediment bury the entire skeleton. 2. Sediment builds up and turns to rock. 3. An organism dies, and its body begins to decompose. 4. Sediment begins to cover the organism’s skeleton. Which is the correct order of events for fossil formation? Choose the correct answer

• 2,3,4,1
• 3,4,1,2

10. The diagram shows a cross section of different rock layers. According to the law of superposition, the rock layer above another rock layer is younger than the one below. According to the law of superposition, which numbered layer is the youngest?

• layer 3
• layer 1