Vocabulary

In your own words, write a definition for each of the following terms in the spaceprovided.

  1. paleontologist:______

______

  1. fossil:______

______

  1. rock cycle:______

______

  1. relative dating:______

______

  1. absolute dating:______

______

  1. half-life:______

______

  1. geologic time scale:______

______

  1. extinct:______

______

  1. mass extinction:______

______

  1. Precambrian Time: ______

______

  1. Paleozoic Era:______

______

  1. Mesozoic Era:______

______

  1. Cenozoic Era: ______

______

  1. scientific theory: ______

______

  1. climate:______

______

Fill in the blank

  1. The Age of Mammals refers to the ______Era.
  2. The Age of Reptiles refers to the ______Era.
  3. Plants colonized dry land during the ______Era.
  4. Scientists estimate the age of the Earth to be about ______billion years old.
  5. Plants and air-breathing animals appeared during the ______Era.
  6. Some scientists estimate that the first cells appearedon Earth ______years ago.
  7. Fossils are most likely to be found in ______.
  8. When a majority of life forms die out due to an event in Earth’s history this is called a ______.
  9. At the end of Paleozoic Era 90% of all life on Earth died out. This is called a ______.
  10. A large meteor impact that could cause a mass extinction is a ______.
  11. The theory of huge pieces of crust moving around the globe is called ______.
  12. Most scientists believe that the cause of the dinosaur mass extinction was a ______.
  13. Scientists estimate that only ______of all species that have ever existed on Earth are living today. The other species have most likely ______.
  14. If the climate on earth changed suddenly it could cause many species to become extinct. This would be called a ______event.
  15. Determining whether a fossil is older or younger than other fossils found in the many layers of sedimentary rock is the ______method of determining the age of a fossil.

Short Answer – Answer using compete sentences

  1. What are some examples of types of materials that form fossils?
  1. How is the age of a fossil estimated?
  1. What kind of evidence can the fossil record supply?
  1. List some ways that gaps in the fossil record can occur.
  1. What impact did the presence of cyanobacteria have on the Earth?
  1. Give an example of a catastrophic event and describe what effect this event may have on animals.
  1. List the major geologic eras in order from longest ago to most recent. Give an example of the dominant life form for each era.

Million years ago (mya) / Era or Time / Dominant Life form
> 540
540 - 248
248 - 65
65 - today
  1. Geologists have separated the Cenozoic Era into two Periods; the Quaternary and Tertiary Periods. Complete the following table and identify which Period Humans appeared.

Era / Period / Million Years Ago (mya) / Humans Appeared
Cenozoic
  1. Describe what scientists think the first organisms on Earth were like (include a description of their living environment).
  1. Explain how the eras on the geologic time scale are divided.
  1. Name at least one important biological event that occurred during each of the geologic eras:
  2. Precambrian time:
  1. Paleozoic era:
  1. Mesozoic era:
  1. Cenozoic era:
  1. Why are there usually more fossils from the Cenozoic era than from other geologiceras?

A rock containing a newly discovered fossil is found to contain 5 g of an unstableform of potassium and 5 g of the stable element argon that was formedfrom the decay of unstable potassium.

  1. In the above example, if the half-life of the unstable form of potassium is 1.3 billion years, how old is therock?
  1. In the above example, what can you infer about the age of the fossil?
  1. What have scientists learned about the complexity, size, and biodiversity of life from studying the fossil record?
  1. What is the overall pattern in the history of Life on Earth?
  1. Using the Law of Superposition to support your answer, explain which layer of rock (A,B,C, or D) is the oldest layer of rock and which is the youngest layer of rock.

  1. Diagram and describe the rock cycle. (include sedimentary, metamorphic, and igneous rock types and how to transition between each one).

Unit 2 Earth and Life History Study Guide12006-2007 Yearlong