Chapter 12: The History of Life Flashcards
What are ways Fossils can form?
Natural Casts
Amber-Preserved
Per-mineralization
Which type of rock is most common for fossils to form in
Sedimentary Rock
Radiometric Dating
Uses the natural decay rate of unstable isotopes found in materials in order to calculate the age of that material
How old is the Earth estimated to be
4.5 Billion years old
Largest to Smallest, what is the correct order of the timeline divisons
Eons, Eras, Periods
During which period did the Dinosaurs go extinct?
Cretaceous
During which period did the humans appear
Tertiary
How many years ago did the tertiary period begin
65 Million
During what Eon did the first life arise?
The Precambrian Eon
During what time frames did Pangea occur?
290-245 Mya
Miller-Urey Experiment
Demonstrates that organic molecules can be formed from inorganic molecules, showing what early earth may have been like
Some scientists proposed that Earth may have used ____ as the genetic material
RNA
How many years ago did photosynthetic life - such as Cyanobacteria - evolve
3.5 Billion Years ago
Endosymbiosis
a relationship in which one organism lives within the body of another, and both benefit from the relationship. This theory has proposed that mitochondria and chloroplasts were once simple cells that were consumed by larger prokaryotes and eventually became organelles.
Sexual Reproduction
Led to an increased diversity of life on Earth
