definitions flashcard exam I

definitions flashcard exam I - Primary productivity -is the...

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2/10/11 Primary productivity -is the production of organic compounds from atmospheric or aquatic CO2 - principally through the process of photosynthesis -The organisms responsible for primary production are known as primary producers or autotrophs , isotope fractionation -the process in which the lighter isotope of an element or compound is preferentially utilized by an organism 12C vs 13C -As a result organic matter contains higher ratio of lighter isotope 12C leaving behind the heavier isotope in the environment. stromatolites -rounded, multilayered, fossilized microbial mat w/sedimentary structure of rock-like layer of either sand or precipitated minerals formed in shallow water. - include some of the most ancient records of life on Earth, found in rocks dating back at least 2.8 billion years. -many are fossils, but there are some still forming - often of cyanobacterial origin. microfossils -fossils only visible under a microscope -occassionally observed in ancient rocks that are rich in organic matter (kerogen) -are common feature of the geological record, ( Precambrian 2 Holocene) - They are the tiny remains of bacteria, protists, fungi, animals, and plants RNA world -hypothesis proposes that a world filled with life based on RNA predates the current world of life based on DNA and protein -RNA may have supported cellular or pre-cellular life. - proposed to have evolved into the DNA and protein world of today. - suggests that rRNA is an evolutionary remnant of the RNA world. banded iron formations -are a distinctive type of rock often found in primordial sedimentary rocks. -structures consist of repeated thin layers of iron oxides , either magnetite (Fe3O4) or hematite (Fe2O3), alternating with bands of iron-poor shale - marks a mile stone in earths history with the evolution of oxygenic photosynthesis in the cyanobacteria endosymbiosis -growth of a microorganism within another organism that is generally beneficial to both. - theory of endosymbiotic evolution was developed to explain the origin of mitochondria and chloroplasts. systematics the scientific study of the kinds and diversity of organisms and of any and all relationships among them; the classification of organisms in an ordered system designed to indicate natural relationships taxonomy the theory and practice of classifying classification the ordering of organisms into groups natural classification -classification in which the members of a group resemble one another not only in the characters that define the group (as they must, by definition) but also for many other non-defining characters too. -opposing artificial classification in which the members of a identification the process of placing an individual into a given group
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2/10/11 taxon (taxa plural) a taxonomic group of any rank that is sufficiently distinct to be worthy of being assigned to a specific category (genus, species) phylogeny the evolutionary history of an organism. The phylogeny of prokaryotes
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definitions flashcard exam I - Primary productivity -is the...

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