biogenesis
the scientific principle that living organisms come only from other living organisms
spontaneous generation
an early and now disproved theory that living organisms come to life spontaneously from nonliving material
radiometric dating
a method of determining the absolute age of an object by comparing the relative percentages of a radioactive(parent) isotope and a stable(daughter) isotope
isotope
an atom that has the same number of protons as other atoms of the same element but has a different amount of neutrons
mass number
the sum of the numbers of protons and neutrons in the nucleus of an atom
radioactive decay
the disintegration of an unstable atomic nucleus into one or more different nuclides, accompanied by the emission of radiation, the nuclear capture or ejection of electrons, or fission
radioactive isotope
an isotope that has an unstable nucleus and that emits radiation
half-life
the time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope
microsphere
a microscopic spherical structure composed of many protein molecules that are organized as a membrane
coacervate
a mass of droplets of colloidal substances, such as lipids, amino acids and sugars, that are held together by electrostatic attraction
ribozyme
a type of RNA that can act as an enzyme
archaea
prokaryotes, most of which are known to live in extreme environments difference- genetic, make up of cell wall
chemosynthesis
the production of carbohydrates through the use of energy from inorganic molecules instead of light
cyanobacteria
a group of bacteria that can carry out photosynthesis
ozone
a gas molecule that is made up of three oxygen atoms
endosymbiosis
a mutually beneficial relationship in which one organism lives within another; theory- two eukaryotes became a prokaryote