Fossils
These fossils form when an organism is quickly buried by sediment and its remains harden into rock over time.
What are preserved remains
This type of boundary occurs when two plates move away from each other.
What is a divergent boundary?
This law states that in undisturbed rock layers, the oldest layer is on the bottom.
What is the Law of Superposition?
Earth is approximately this many years old.
What is 4.6 billion years old?
This organelle is known as the “powerhouse of the cell.”
What is the mitochondria?
This type of fossil forms when minerals replace the original material of an organism, turning it into stone.
What is a petrified fossil?
This boundary forms when two plates collide, often creating mountains or volcanoes.
What is a convergent boundary?
This type of dating compares rock layers to determine which is older or younger.
What is relative dating?
This tool is used to organize Earth’s history into eons, eras, periods, and epochs.
What is the geologic time scale?
This force pulls objects toward the center of the Earth.
What is Gravity
This process must happen quickly to increase the chances that an organism becomes a fossil.
What is rapid burial
At this boundary, plates slide past each other, often causing earthquakes.
What is a transformation boundary
This principle states that rock layers are originally deposited horizontally.
What is the Principle of Original Horizontality?
This era is known as the “Age of Dinosaurs.”
What is the Mesozoic Era?
When light bends as it passes from air into water, this process is occurring.
What is refraction
These fossils are created when an organism leaves an impression in sediment that later hardens into rock.
What are mold and cast fossils?
This landform forms when one oceanic plate is forced beneath another plate.
What is an ocean trench
If a fault cuts through several rock layers, this principle says the fault is younger than the layers.
What is the Principle of Cross-Cutting Relationships?
This event about 66 million years ago caused the extinction of the dinosaurs.
What is a mass extinction (or the asteroid impact)?
The building block of life
What is a cell
Soft-bodied organisms rarely fossilize because they lack this hard structure that fossilizes more easily.
What are bones, shells, or hard parts?
When two continental plates collide, this major landform is usually created.
What are mountain ranges
When rock layers are tilted or folded, it suggests this happened after the layers were formed.
What is tectonic activity (or plate movement)?
This is the current era in which humans live.
What is the Cenozoic Era?
In a food web, organisms that make their own food using sunlight are called this.