click below
click below
Normal Size Small Size show me how
Humberto
Question | Answer |
---|---|
Fossil | the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock. |
Relative dating | Relative dating falls under the sub-discipline of geology known as stratigraphy. Stratigraphy is the science of rock strata, or layers. |
Radiometric dating | a method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample. |
Isotope | each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei. |
Half-life | the time taken for the radioactivity of a specified isotope to fall to half its original value. |
Index fossil | a fossil that is useful for dating and correlating the strata in which it is found. |
Era | a long and distinct period of history with a particular feature or characteristic. |
Period | a portion of time in the life of a person, nation, or civilization characterized by the same prevalent features or conditions. |
Epoch | the beginning of a distinctive period in the history of someone or something. |
Ribozymes | an RNA molecule capable of acting as an enzyme. |
Cyanobacteria | also known as Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. |
Endosymbiosis | symbiosis in which one of the symbiotic organisms lives inside the other. |
Cambrian explosion | The Cambrian explosion, or less commonly Cambrian radiation, was the relatively short evolutionary event, beginning around 542 million years ago in the Cambrian Period, during which most major animal phyla appeared, as indicated by the fossil record. |