The fossil record helps scientists identify a single species from which other organisms have descended. Which is used to refer to this single species?
Common ancestor
Which statement best describes the fossil record?
It's an incomplete record
Which statement accurately describes a half-life?
A half life is the time required for half of a radioactive element to decay
This fossil shows tunnels left after animals burrowed through the sediment. Which statement best describes this fossil?
It is a trace, because it shows evidence of animal activity
Which phrase describes faults?
Cause rocks to break and move
What determines the length of a geologic time period?
Fossil record
Which best explains how scientists confirmed that the moon formed around the same time as Earth?
Scientists used radioactive dating to study the age of material from the moon and earth
Compared to absolute dating, what is the advantage of relative dating?
Age, in years, cannot be determined for an individual fossil.
Which important event in Earths history occurred during the Jurassic period?
The first birds emerged to Earth
Which period belongs to the Paleozoic era and not the Cenozoic era?
Devonian
The diagram illustrates radioactive decay. Which statement correctly identifies structures 1 and 2 in the diagram?
Structure 1 is an unstable atom that turns into structure 2, a new atom
Which statement describes potassium-argon dating?
Potassium-40 decays into argon gas over time
Which event most likely if an index fossil is found in a layer at location 1, but the layer and index fossil are not found at location 2 nearly, which is known to be the same relative age?
The organism did not exist at location 2
Which characteristic of potassium makes it useful for dating rocks?
It has a long half-life
The image shows sedimentary rock layers. According to the law of superstition, which layer is the oldest?
1