Chapter 3/Chapter 13
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Class _____
Test Review & Study Guide
Complete the following review to help you prepare for the test on Thursday, January 29th. You may complete the
online quizzes for both Chap 3 and 13 for extra credit. Submit your results via email (blairm@leonschools.net).
Don’t forget to review your textbook, activities/labs and handouts also. This sheet is due on the day of the test.
1. How is a fossil defined? Any preserved remains of an organism
2. What are the different types of fossils? Mold, cast, trace, original remains/material (body fossil),
mineralization, carbonization (carbon film), fossil fuels (gas, petroleum oil)
3. How are each type formed? See TB pgs. 510-511
4. Describe the steps in the formation a mold and cast fossils. Refer to fossil notes
5. What type of rock are fossils usually found in? Why? Sedimentary rock-fossils can be preserved
with this type of rock formation (fossils would not survive formation in metamorphic or igneous
rock)
6. What conditions help preserve organisms as fossils? Quick burial of remains, hard parts are
more likely to become fossils, little exposure to air and bacteria
7. If marine fossils are found in areas that are not near the ocean, what does this tell scientists?
That area was once covered with water
8. What is the name of the most recent era? Cenozoic The earliest era? Precambrian
9. What is an index fossil? What information does it give to geologists? An index fossil is a
common fossil from a known time period. They are abundant and found in many places. They
are used to find the age of rock layers.
10. Which life forms developed early in the Earth’s history? bacteria
11. Which life forms developed in the most recent eon? mammals
12. What information does relative age give scientists? Age of rock layer compared to other layers
13. Which is older: a fossil that is 400 million years old or a fossil that is 500 years old? Fossil that is
400 million years old
14. How are fossils used to age rock layers? Index fossils are known age, so if they are found in rock
layers-the layer will be the same age as the fossil. Also, carbon dating can be done on fossils to
determine age of unknown fossil.
15. What information does absolute age give scientists? actual age of rock
16. What is the Principle of Superposition? Oldest layer of rock will be on the bottom in an
undisturbed area of rock layers
17. Put the layers and faults in order of formation:
Shale-sandstone-limestone-granite (oldest to youngest-Law of Superposition)
Granite is igneous rock
18.
1 half lives
40 g
40 g
2 half lives
20g
60g
3 half lives
10g
70g
19. Einsteinium-253 has a half life of 20 days. If you had a 100 gram sample, how much
Einsteinium-253 would remain after 60 days? 12.5 g, see chart below
Days
½ Lives
Amount of parent isotope
0
0
100 g
20
1
50 g
40
2
25g
60
3
12.5g
20. How do we know that life has changed over time? Fossil evidence
21. What is natural selection? Process by which organisms well suited to their environment will
survive and reproduce, passing on these favorable traits.
22. Why is natural selection sometimes called “survival of the fittest”? Organisms not well suited for
their environment will not be able to survive and their traits won’t be passed to offspring.
23. What is evolution? Change over time in living things
24. What is a homologous structure? Body parts of organisms that are similar in structure and
position but possibly different in function
25. What is variation in a population of living things? A slight difference in an inherited trait of an
individual member of a species
26. How do Darwin’s and Lamark’s theories of how life has changed over time differ? Lamark
believed that organisms of a species had the same traits and could change themselves during
their lifetimes. Darwin believed that there were variations in a population. Those variations
could help an organism survive and reproduce-passing those variations to offspring.
27. Use the geologic timeline below to answer the following questions.
a) Which eon do we currently live in? Phanerozoic
b) What information is used to divide time into segments into the geologic timeline? Fossils
c) Which era do we live in? Cenozoic
d) If you found a fossil in the Permian period, would it be younger or older than a fossil found
in the Triassic period? How do you know? Older, the Permian period occurred before the
Triassic period
e) Identify the eon and era the Devonian period is in. What eon and era would we find the
Cretaceous period?
Devonian-in Phanerozoic Eon, Paleozoic Era
Cretaceous-in Phanerozoic Eon, Mesozoic Era