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Chapter 14-15
Biology Vocab
Term | Definition |
---|---|
Biogenesis | The theory 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 (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). |
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 | Are spherical in shape and are composed of many protein molecules that are organized as a membrane. |
Coacervate | A mass of colloidal substances 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) that are distinguished from other prokaryotes by differences in their genetics and in the makeup of their cell wall; members of a domain of the same name. |
Chemosynthesis | The production of carbohydrates through the use of energy from inorganic molecules instead of light. |
Cyanobacteria | A group of photosynthetic, unicellular prokaryotes. |
Ozone | A gas molecule that is made up of three oxygen atoms. |
Endosymbiosis | A mutually beneficial relationship in which one organism lives within another. |
Evolution | A heritable change in the characteristics within a population form one generation to the next; the development of new types of organisms from preexisting types of organisms over time. |
Strata | Layers of rock. |
Natural Selection | The process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do; a theory to explain the mechanism of evolution. |
Adaptation | The process of becoming adapted to an environment; an anatomical, physiological, or behavioral change that improves a population's ability to survive. |
Fitness | A measurement of the ability of a species to respond to the pressures of natural selection; the ability of individuals to survive to propagate their genes. |
Fossil | The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock. |
Superposition | A principle that states that younger rocks lie above older rocks if the layers have not been disturbed. |
Relative Age | The age of an object in relation to the ages of other objects. |
Absolute Age | The numeric age of an object or event, often stated in years before the present, as established by an absolute-dating process, such as radiometric dating. |
Biogeography | The study of the geographical distribution of living organisms and fossils on Earth. |
Homologous Structure | Anatomical structures that share a common ancestry. |
Analogous Structure | Have closely related functions but do not derive from the same ancestral structure. |
Vestigial Structure | A structure in an organism that is reduced in size and function and that may have been complete and functional in the organism's ancestors. |
Phylogeny | The evolutionary history of a species or taxonomic group. |
Convergent Evolution | The process by which unrelated species become more similar as they adapt to the same kind of environment. |
Divergent Evolution | The process by which two or more related but reproductively isolated populations become more and more dissimilar. |
Adaptive Radiation | An evolutionary pattern in which many species evolve from a single ancestral species. |
Artificial Selection | The selective breeding of organisms (by humans) for specific desirable characteristics. |
Coevolution | The evolution of two of more species that is due to mutual influence, often in a way that makes the relationship more mutually beneficial. |