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Chapter 12 Vocabular
Biology
Term | Definition |
---|---|
Fossil | A trace of an organism from the past |
Relative Dating | An estimate of the age of a fossil based on the location of fossils in strata. |
Radiometric Dating | Technique that uses the natural decay rate of isotopes to calculate the age of material. |
Isotope | A form of an element that has the same number of protons but a different number of neutrons as another element |
Half-Life | The amount of time it takes to for half of the isotopes in a sample to decay into its product isotope |
Index Fossil | A fossil of an organism that existed during only specific spans of geologic time across large geographic areas. |
Era | The second largest unit of geologic time, lasting tens to hundreds of millions of years and consisting of two or more periods |
Period | Unit of geologic time that lasts tens of millions of years and is associated with a particular type of rock system. |
Epoch | The smallest unit of geologic time, lasting several million years |
Ribozyme | RNA molecule that can catalyze specific chemical reactions |
Cyanobacteria | Bacteria that can carry out photosynthesis |
Endosymbiosis | Ecological relationship in which once organism lives within the body of another |
Cambrian Explosion | The earliest part of the Paleozoic era, when a huge diversity of animal species evolved |