Vocabulary Review Ch 14 – History of Life

The scientific principle that living organisms come only from other living organisms Biogenesis

An early and now disproved theory that living organisms come to life spontaneously from nonliving material Spontaneous generation

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 Radiometric dating

An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) Isotope

The sum of the numbers of protons and neutrons in the nucleus of an atom Mass number

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 decay

An isotope that has an unstable nucleus and that emits radiation Radioactive isotope

The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope Half-life

A microscopic spherical structure composed of many protein molecules that are organized as a membrane Microsphere

A mass of droplets of colloidal substances, such as lipids, amino acids, and sugars, that are held together by electrostatic attraction Coacervate

A type of RNA that can act as an enzyme Ribozyme

Prokaryotes, most of which are known to live in extreme environments; differentiated from other prokaryotes by genetic differences and differences in the make up of their cell walls Archaea

The production of carbohydrates through the use of energy from inorganic molecules instead of light Chemosynthesis

A group of bacteria that can carry out photosynthesis Cyanobacteria

A gas molecule that is made up of three oxygen atoms Ozone

A mutually beneficial relationship in which one organism lives within another; a theory that eukaryotic cells originated through endosymbiotic relationships between ancient prokaryotic cells Endosymbiosis