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chap 14 & 15
14 & 15
Question | Answer |
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biogenesis | states that all living things come from other living things. |
spontaneous generation | living things arise from nonliving things in a process |
radiometric dating | method of establishing the age of materials include this technique |
isotopes | atoms of the same element that differ in the number of neutrons they contain |
mass number | the total numer of protons and neutrons in the nucleus |
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 isotopes | an isotope that has an unstable nucleus and that emits radiation |
half-life | the length of time it takes for one-half of any size sample of an isotopeto decay to a stable form |
microspheres | spherical in shape and are composed of many protein molecules that are organized as a membrane |
coacervates | collections of droplets that are composed of molecules of different types, including lipids, amido acids and sugars |
ribozyme | an RNA molecule that can act as a catalysst and promote a specific chemical reaction. Thomas Cech used this |
archaea | are a related group of unicellular organisms, many of which thrive under extremely harsh environmental conditions |
chemosynthesis | CO2 serves as a carbon source for the assembly of organic molecules. |
cyanobacteria | a bacterium that can carry out photosynthesis, such as a blue-green alga |
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 | the development of new types of organisms from preexisting types of organisms over tim. Modern scientists define it as a heritable change in the characteristics within a population from one generation to the next. |
strata | layers of rock |
natural selection | Darwin proposed this theory that as the mechanism for descent with modification |
overproduction | more offspring can be produced than can survive to maturity |
genetic variation | within a population, individuals have different traits |
struggle to survive | individuals must compete with each other |
adaptation | a trait that makes an individual successful in its environment, such as thick fur in cold climates |
differntial reproduction | darwin concluded that organisms with the best adaptations are most likely to survive and reproduce. And through inheritance, the adaptations will become more frequent in the population. So, populations may egin to differ as they become |
fitness | the measure of an individual's hereditaryy contribution to the next generation |
fossil | the remains or traces of an organism that died long ago. Can be formed under a number of different conditions |
superposition | if the rock strata at a location have not been disturbe, the lowest stratum was formed before the strata above it. Nicolaus Steno proposed this principle |
relative age | its age compared to that of another fossils by referring to the geologic time scale and to records of known fossils |
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 locations of organisms around the world |
homologous structures | anatomical structures that occur in different species and that originated by heredity from a structure in the most recent common ancestor of the species |
analogous structures | have closely related functions but do not derive from the same ancestral structure |
vestigial structures | 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 |
phyogeny | the relationships by ancestry amonng groups of organsims |
convergen evolution | the process by which different species evolve similar traits |
divergent evolution | a process in which the descendants of a single ancestor diversify into species tha teach fit different parts of the environment |
adaptive readiation | an evolutionary pattern in which many species evolve from a single ancestral species |
artificial selection | the process that occurs when a human breeder chooses individuals that will parent the next generation |
coevolution | when two or more species have evolved adaptations to each other's influence |