Unit 6 Flashcards
What is the definition of evolution?
The gradual change in organisms over time
How fast does evolution occur?
Millions of years
What are these changes due to?
They are due to sexual reproduction (variations in genes) and mutations.
Inherited adaptations help organisms______ and _______ in their enviroment
Survive, reproduce
What is the definition of fossils?
A preserved trace of once-living organisms
What are three objects that organisms can be preserved in?
Ice, tar, or amber (resin)
Parts of an organism are sometimes replaced by minerals. Give an example of something that this happens to.
Petrified wood - minerals replace the cell wall of decaying wood
What type of rock is most commonly found with molds, casts, or imprints trapped of other organisms in them?
Sedimentary Rock
What is a fossil record?
When decayed organisms are organized by their estimated age.
Ex) newer, upper layers of rock are more similar to present day organisms
True or False- A rock closer to the surface is older than a rock deep into the ground
False
What is the method called when you look at the layers of rock to figure out how old something is?
Relative-Dating
What is the definition of Absolute-dating?
A method that measures the age of fossils or rocks in years by examining the half-lives of radioactive atoms.
In what year did major movements in DNA based science occur?
1958 (ex. Rosiland Franklin and Watson and Crick)
Biochemical similarities: Closely related organisms have very many similarities in their _______?
DNA
What are vestigial structures?
Remnants of once-useful structures