| A | B |
|---|
| biogenesis | the principle that all living things come from other living things |
| spontaneous generation | the principle that states that living things could also arise from nonliving things |
| radiometric dating | a technique to establish the age of materials |
| isotope | atoms of the same element that differ in the # of neutrons |
| mass number | number of protons and neutrons |
| radioactive decay | unstable nuclei that emit particles |
| radioactive isotopes | isotopes that emit particles and are unstable |
| half-life | the length of time it takes 1/2 of the sample size to decay |
| endosymbiosis | theory that eukaryotic cells originated through relationships with prokaryotes |
