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93 Cards in this Set
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10 levels of organization of biological systems |
Chemical Cell Tissue Organ Organ system Individual Population Community Ecosystem Biosphere |
CCTOOIPCEB |
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Chemical biological system |
Contains all substances essential for life; only non living level - atoms form molecules and compounds - metabolism: sum total of all chemical reactions occurring in the body |
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Cell |
Basic structural and functional unit of life; smallest living structure - cells become specialized for different functions - contain organelles that carry out specific functions for cells - 2 types of cell: prokaryotic and eukaryotic - Robert hooke: first to describe a cell (little boxes in cells) |
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Prokaryotic cell |
No nucleus No cellular organelles (except for ribosomes) |
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Eukaryotic cells |
Have a membrane enclosed nucleus and organelles |
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Tissue |
Group of different cells that perform a particular function |
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Organ |
Structure with 2 or more tissues carrying out a specific function - ex: stomach, brain, heart |
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Organ system |
Group of interconnected/ interdependent organs that carry out system functions - 11 organ systems in the body: all function together to maintain homeostasis - ex: cardiovascular system (heart, blood vessels, blood) |
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Individual |
Highest level of organism organization; all organ systems function together - individuals exhibit genetic variation - 2 sources of variation: mutations and genetic recombination |
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Mutations |
Individual possess different mutations in DNA of genes - raw material for evolution |
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Genetic recombination |
Individuals pass their genes composed of their DNA to their offspring through sex - combines mutations from parents in offspring -parent DNA determines characteristics of offspring |
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Population |
A group of individuals living in an environment that form a species group -species: population of individuals that can interbreed and produce fertile offspring. Genetic variation btw individuals leads to evolution of a species |
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Community |
All the different species groups living in the same environment |
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Ecosystem |
All communities with all species and non living factors in the environment |
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Biosphere |
All environments in habitat ed by all organisms in all ecosystems on earth - land, water, atmosphere |
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Emergent properties |
Unique properties(characteristics) that are not present at lower levels of biological systems - characteristics of each level are due to properties at lower levels - ex: carbon, hydrogen, oxygen Membranes, pigments Chloroplast components Chloroplast Photosynthesis |
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Taxonomic classifications of organisms |
Linnaeus: father of taxonomy Taxonomy: formal system for naming and classifying organisms 3 domain system: current taxonomic classification of organisms ( woese and Linnaeus) Classification systems exclude viruses because they aren't considered to be living |
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3 domain system |
Organisms arranged into 8 categories based on similarities (relatedness) - domain (highest) - kingdom - phylum - class - order - family - genus - species (lowest) Groups arranged together as if descended from a common ancestor. - each level includes one or more groups from previous level . Species: only level containing living organisms.Species relationship based on morphological, molecular and fossil similarities Species relationship based on morphological, molecular and fossil similarities |
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Domains |
Bacteria Archaea Eukarya |
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Domain bacteria |
Prokaryotic Typical bacteria - e coli |
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Domain Archaea |
Prokaryotic Atypical bacteria - thermoplasma |
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Domain Eukarya |
Eukaryotic Divided into super groups based on structure, and mode of nutrition - kingdom protista - kingdom fungi - kingdom plantae - kingdom animalia |
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Kingdom protista |
Mostly single cell ed Animal like, plant like, and fungus like Heterotrophic Photosynthetic Parasitic Saprophytic |
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Kingdom fungi |
Saprophytic Some parasites - mushrooms |
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Kingdom plantae |
Multicellular MulticellularProducers- photosynthetic MulticellularProducers- photosynthetic Producers- photosynthetic |
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Kingdom animalia |
Heterotrophic Few parasites- bears |
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Binomial system of nomenclature |
Each organism has a genus and a species name Species: group of individuals that can interbreed and produce fertile offspring Genus: group of species more closely related to each other than to other species |
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Phylogeny |
Evolutionary history of a group of species - based on 3 types of evidence - fossil record: shows similarities between species - shows relationships between fossils in sediments - morphology: use form of body to show similarities between species - molecular: use DNA, RNA or other molecules to show relationships between species |
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Phylogenetic tree |
Diagram showing evolutionary relationships between species - branches illustrate hypotheses about common ancestors for species groups |
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Clade |
Group of species including the ancestral species. - monophyletic clade: contains common ancestor and all its descendants |
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Character |
Any molecular, cellular, organ, functional trait exhibited by group - primitive character: found in ancestor and all other members of the clade Derived characters found in some members of the clade but not the older ancestor - indicates descendants have diverged from their ancestors - ex: four walking legs and lungs distinguish amphibians from fish. Unique derived character: found in only certain members of a clade but not others. - ex: birds are the only reptile that have feathers |
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Charles darwin |
Wrote the origin of species by natural selection - organism dives it due to gradual changes in a species group over a very long time - proposed modern species arose through succession of ancestors - all organisms descended with modification from a common ancestor - changes preserved in groups most adapted to environment Went on a 5 year voyage around the world ( the beagle) - ideas based in part on observation of finch, tortoise, and iguana diversity in the galapagos islands - currently 13 recognized finch species, all derived from founder pop from south America - beaks adapted to the different islands food sources - also glyptodon fossils in Argentina - similar to the armadillo
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5 main points to Darwin's theory |
Fact: Natural pops increase exponentially if all individuals born survive to reproduce - reality: more individuals are born than the environment can support Fact: resources are always limited - reality: competition occurs between species for resources, creates a struggle for existence Fact: genetic/physical variation occurs btw individuals to compete more successfully for limited resources - reality: more adapted individuals survive, reproduce more often than less adapted (survival of the fittest) Fact: all characteristics can be passed on to the next generation - reality: advantageous characteristics make an individual more fit for environment, and become more common in future pops. Fact: long periods of time have allowed species groups to change - reality: long periods of time not always required for evolutionary change to occur. |
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History of the concept of evolution |
Aristotle- greek philosopher 4th century BC - proposed earliest classification scheme (based on similarities) Hutton and lyell (1830) - geologists - proposed sediments formed by naturally occurring processes happening at present time (beach, delta formation, and lava flows) - deeper sediments are older and therefore fossils found in deeper sediments are older - first to suggest earth much older than 6 thousand years old Lamark (1809) - suggested individual variation due to "inheritance of acquired characteristics" - adaptations are acquired during lifetime based on need for characteristic - excessive use or disuse of organ influences development of organ (ex: giraffes have long necks to reach leaves on taller trees) - adaptations acquired through use during lifetime are passed onto next generation |
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Theory of organic evolution by natural selection |
Modern definition of evolution - change in genetic characteristics of a species from 1 Gen to the next Modern definition of natural selection - differential survival and reproduction of individual genotypes - genotype: genetic characteristic - some individuals more adapt to environment than others (more adapted increase pop over time) - genetic differences between individuals due to mutations and gene recombination - natural selection adapts pop to environment |
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Evidence for evolution by natural selection |
Fossil record Fossil record Homologous characteristics Vestigial organs Fossil recordHomologous characteristicsVestigial organsConvergent evolutionArtificial selection Fossil recordHomologous characteristicsVestigial organsConvergent evolutionArtificial selection Fossil recordHomologous characteristicsVestigial organsConvergent evolutionArtificial selection Homologous characteristicsVestigial organsConvergent evolutionArtificial selection Convergent evolution Artificial selection |
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Fossil records |
Fossil record: shows organisms no longer living on earth were once present- doesn't preserve every organism ever present on earth - very few fossils show gradual, clear changes in successive layers of sediment (foraminifera, trilobites, mollusks)- sometimes show which group evolved from a previous group (ex: birds derived from feathered dinosaurs; archaeopterix) |
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Homologous characteristics |
Similar structures that occur in different species groups Homologous: structures look/ function alike - related because they evolved from a common ancestor - ex: tetrapod vertebrate forelimb anatomy (same bones, in same order with similar muscle patterns: amphibians, reptiles, birds, mammals) -ex: vrtebrate embryo development (all vertebrate embryos possess pharyngeal (gill) slits, other similar structures: suggests vertebrates evolved from fish ancestor) - ex: molecular similarities - true indicators of evolutionary relatedness (DNA, Cytochrome C: protein in mitochondria of all cells) |
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Vestigial organs |
Organs functional in ancestors that are nonfunctional in descendants - snakes and whales descended from terrestrial herbivores - camel, hippo like species - legs supported weight on land - function diminished in aquatic environment - humans: appendix, ear lobes, canines, 3rd molars, body hair, coccyx |
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Convergent evolution |
Unrelated organisms evolve similar adaptations to similar habitats - look/ function alike but not related by ancestry -not related - not from immediate common ancestor - wings in birds, bats, pterosaur - streamlined bodies, flippers in dolphins and seals and penguins |
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Artificial selection |
Shows humans can rapidly cause evolutionary change - directed breeding of domesticated animals, cultivate plants promotes desirable characteristics -60+ breeds of dogs all bred fom wolf ancestor - 800 breeding types - all dogs can reproduce and form fertile offspring which makes them one species |
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Plate tectonics - continental drift |
Earth's continents have moved and changed positions over time - earth's crust composed of plates that move apart, slide by, over, and under each other - move apart at ridges and collide at edges - zone of volcanism and earthquakes Modern continents originally began as a single land mass called pangaea - split into 2 land masses: - laurasia to north: formed n. America, Europe and Asia - stayed mostly together - gondwana to south: formed s. America, africa, Australia and Antarctica - separated from each other |
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Ridges divergent |
Plates push apart as materials forced to surface - adds new crust - continents move about 10 centimeters apart each year - mid Atlantic ridge - strata farther from ridge older than strata near ridge |
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Edges |
Convergent: 1 plate force under the other (cascade mts.) - destroys crust: forms subduction zones, trenches Collisional: both plates forced up - does not add or destroy crust (himalayas, alps, rocky mts.) Transform boundary: plates slide past each other - does not add or destroy crust (san Andreas fault) |
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Evidence for plate tectonics |
- magnetic field studies of land and ocean floor sediments - geological formations on 1 continent resemble those on another continent - biogeographical distribution of organisms |
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Magnetic field studies |
- iron in molten rock aligns with earth magnetic pole as it solidifies - magnetic fields in different strata are aligned in different directions - indicates magnetic poles changed and continents moved around |
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Geological formations |
- south america and africa - south africa, antarctica, australia and india - new england, england and scandinavia - volcanic islands in pacific - form when crust passed over hot spot of magma - Hawaii (3.5 myo), midway island, emperor islands (70 myo) |
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Biogeographical distribution of organisms |
some organisms are similar and appear related but occur on different continents - flightless birds: ostrich in africa, rhea in south america, emu in australia - fossil ferns: glossypteris; found on all continents - fossil reptiles: lystrosaurus distribution results from continental drift |
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Biological species concept |
Species: population of individuals that can interbreed and produce fertile offspring cannot reproduce or produce fertile offspring with other species groups. Species formation requires that reproductive isolating barriers form between populations - reproductive isolating barriers: factors that prevent/ inhibit reproduction between species - isolating barriers form as populations become different from each other. - each population characterized by different morphological, physiological, behavioral traits |
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Allopatric speciation |
geographically separated populations form new species |
different |
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Sympatric speciation |
geographically overlapping populations form new species |
same |
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6 types of reproductive isolating barriers |
- geographical isolation - temporal isolation - behavioral isolation - mechanical isolation - gametic isolation - hybridization - adaptive radiation |
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Geographical isolation |
ALLOPATRIC populations do not ever come in contact or interact - river, mountain range or other barrier separates populations - kaibab and albert squirrels: grand canyon |
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Temporal isolation |
SYMPATRIC Reproduction occurs during different times of day, season or year in range of overlap - 3 frog species: reproduce in spring or fall - cicada species: adults emerge from soil to reproduce at different times (some species every 17 years, other species every 13 years) |
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Behavioral Isolation |
SYMPATRIC sexual selection - directed by specific courtship patterns and recognition of correct mates - Darwin's finches: females recognize songs of males of own species (ignore songs of other species) - sexual dimorphism: males larger, more colorful (lions, pheasant, peacock, bird of paradise, elk |
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mechanical isolation |
SYMPATRIC differences in reproductive parts prevents mating, pollination - snails: genital structures incompatible between species - plant pollinators each have structural adaptations for particular flowers (each flower has structural adaptations for particular pollinator) |
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gametic isolation |
SYMPATRIC sperm of 1 species cannot fertilize eggs of different species - ex: mouse vs. rat |
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Hybridization |
SYMPATRIC hybrids form when similar species reproduce - offspring do not live or live but cannot reproduce due to chromosome differences - ex: mules (horse and donkey), zorse, liger |
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adaptive ratiation |
allopatric at first then sympatric - a few individuals leave a larger population and colonize new environment - less competition for resources, absence of predators, diversity of habitats in new environment - new adaptations evolve to use new resources: promotes speciation - ex: galapagos finches - adaptive radiation follows extinctions - new habitats in environment become available for surviving population - reptiles fill niches vacated by amphibians after permian extinction - mammals fill niches vacated by dinosaurs after Cretaceous extinction |
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Big Bang Theory |
LaMaltre: Astronomer (1927) - explosion - 14 bya; produced matter and energy of universe - universe expanded = gravity condensed clouds of matter to form earth; 4.6 bya -oldest recorded rocks on earth are 4.4 byo (western australia) |
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No true definition for life |
living things can be described as chemical compositions composed of cells that can reproduce. - cell theory: Schleiden and Schwann - all living things are composed of cells (basic structural and functional unit of life. Smallest unit displaying properties of living things) - life itself may have come from outside of earth - many planets appear to have water and oxygen: may support life |
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Hypothesis about the origin of life (5 major steps required to form first cells) |
-non living inorganic molecules self assemble in space and/ or on earth - small organic molecules form from inorganic molecules (amino acids, nucleotides, sugars, fatty acids) - large organic biomolecules must be compartmentalized inside membranes. -compartmentalized genetic molecules (RNA) must be able to replicate |
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Synthesis of organic molecules from non living inorganic molecules |
first atmosphere - high temps and water vapor with dissolved substances - CO2, CH4, NH3, N2, H2, H2S - probably from volcanic eruptions - energy from ultraviolet radiation, lightning and volcanic activity - primitive soup hypothesis (1920s) organic molecules formed from non living inorganic molecules - miller and urey (1953) - designed experiment to test primitive soup hypothesis - atmosphere with H2, CH4, NH3, heat, sparks for energy in closed system - formed some hydrocarbons after 1 week - some organic compounds may have reached earth from outer space - amino acids have been isolated from meteorites |
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Small organic molecules from large biomolecules |
Hypothesis: negatively charged sands, clays, rocks attract small positively charged molecules. - evaporation and sun energy connected them into larger biomolecules Experiment: amino acids, RNA nucleotides applied to hot, clay surfaces. - formed some proteins and nucleic acids |
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Compartmentalization of large biomolecules inside a phospholipid bilayer membrane |
phospholipids spontaneously form a phospholipid bilayer in water - protocell: cell like structure that displays some properties of life - phospholipid membrane isolates inside of a cell from outside - membrane bilayer can absorb substances (organic materials) from environment - membrane provides surface for chemical reactions - protocells increase in size and can form new protocells |
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Replication of compartmentalized, genetic material |
RNA probably 1st material, not DNA: RNA assumes different forms - all RNA is single stranded with 3D shapes RNA can function like enzymes - RNA's can make RNA copies of itself, modify other RNA DNA eventually became genetic material: DNA double stranded helix more stable than RNA's - DNA mutates less easily than RNA RNA became intermediate in protein synthesis |
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Prokaryotic evolution |
First prokaryotes thought to have evolved around 3.8 byo - stromatolites: structures composed of cyanobacteria and layers of sediment - 1st described from 3.5 byo fossils - "living fossils" - stromatolites still living today in western Australia |
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Nutritional evolution |
1st prokaryotes required organic energy compounds -ATP - heterotrophic organisms probably evolved first: ate other prokaryotes or their products - photoautotrophic organisms used light energy to make organic compounds - chemotrophic organisms used chemical energy (H2S) to make organic compounds |
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Evolution of photosynthesis and production of oxygen |
Cyanobacteria only oxygen producing photosynthetic bacteria: 3.5 byo - O2 from photosynthesis started accumulating in atmosphere about 2.5 byo: evidence for atmospheric O2 in red banded rocks (iron in rocks rusts as it combines with oxygen - forms iron oxide) Ozone layer formed as O2 increased in atmosphere: ozone blocked UV-B radiation - most damaging UV - Allowed organisms to move on land O2 rapidly increased in atmosphere as land plants with chloroplasts evolved |
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Eukaryotic Evolution |
oldest eukaryotic fossil about 2.1 byo - membrane enclosed nucleus may have formed from infolding of prokaryotic cell membrane (nitrobacter, anabaena) - eukaryotic DNA may have formed from gene transfers between cells: eukaryotic DNA mixture of prokaryotic, mitochondrial, eukaryotic DNA. - Chloroplasts and mitochondria probably arose by endosymbiosis - some cyanobacteria are endosymbiotic within living protozoans |
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endosymbiotic theory |
small prokaryote lived symbiotically within large eukaryote. Evidence for endosymbiosis: - both mitochondria and chloroplasts have 2 membranes - mitochondria, chloroplasts have circular DNA like prokaryotes - some living bacteria similar to mitochondria and chloroplasts |
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Multicellularity |
allows cells to differentiate to form tissues, organs, and organ systems - 1st multicellular organism probably evolved from unicellular colonial forms about 1.5 bya |
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Geological record of earths history |
Precambrian: 4.6 bya - 500 mya Postcambrian: 500 mya - present - paleozoic - mesozoic - cenozoic |
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precambrian |
begins with origin of earth (4.6 bya - 500 mya) - sediments with oldest rocks contain oldest fossil prokaryotes and eukaryotes - ediacaran hills in australia - burgess shale in canada |
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postcambrian |
500 mya; divided into 3 eras - paleozoic era: 500 mya - 250 mya; "age of amphibians" - begins with "cambrian explosion": most modern organism groups evolve (fish, amphibians, non vascular plants, gymnosperms, reptiles) - mesozoic era: 250 mya- 65 mya; "age of reptiles" (dinosaurs, first mammals, insects, angiosperms) - cenozoic era: 65 mya - present; "age of mammals" (birds, large mammal herbivores and carnivores, primates, humans) |
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Postcambrian mass extinctions |
reasons for extinctions unclear - something disrupted temperature, pH or environments (some organisms disappear, some survive, other organisms appear) - evidence for extinctions from marine fossils Precambrian/ cambrian extinction - 500 mya - led to cambrian explosion of organism phyla Permian/ Triassic extinction - btwn paleozoic and mesozoic; 250 mya - most intense ever recorded - 90% marine organisms go extinct Cretaceous extinction - 65 mya; btwn mesozoic and cenozoic - 50% marine organisms, most dinosaurs and many terrestrial plants go extinct (hypothesis: asteroid and/or volcanic eruptions - walter alvarez detected iridium layer in sediments 65 myo (common in meteorites and lava) - deccan trappes in india: massive volcanic erruptions Human caused extinctions - reduces diversity - dodo bird: extinct w/in 100 years of human arrival - passenger pigeons: extinct by early 20th cen. due to hunting and habitat change |
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Dating Fossils |
Radiometric dating - half life - 14 carbon - 40 potassium |
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Radiometric Dating |
determine age of fossils by determining age of sediments fossils are found in - use isotopes of atoms: each decays at a constant rate (unaffected by temp, pressure, other factors) |
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Half Life |
time required for 50% of original isotope to decay to another element: - measure ratio of remaining isotope of atom to other element that forms |
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14 carbon |
Isotope of carbon contained in fossils: - organisms stop accumulating 14 c when it dies, and starts to decay - use half life of carbon 14 to date fossils to about 60,000 years ago - no measurable 14 c in older fossils - very old fossils dated using 40 potassium (longer half life; 1.3 billion years) |
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Viruses |
Latin for "poison" Obligate intracellular parasites - cannot reproduce without a host - therefore not living thought to have evolved from the host they infect - virus genes more similar to their host genes than other virus genes Viruses cause disease in all organisms including humans: - chicken pox, measles, small pox, rabies, influenza, colds, polio, hepatitis, HIV (only few respond to vaccines - most are unaffected) - small pox eliminated from nature by world wide vaccination program |
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virus classification |
classified according to: - host range: viruses infect all organisms (usually adapted to 1 species or related species) - size: smaller than ribosomes - 3 virus groups: DNA viruses (bacterophages), RNA viruses, retroviruses (RNA) |
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Virus Structure |
Nucleic Acid: DNA or RNA; single or double strand, 1 piece or more than 1 piece Capsid: Protein container enclosing nucleic acid Helical-Rod: tobacco mosaic virus Polyhedral: 20 sided; cold virus Complex: tail, head, sheath; bacteriophage Animal viruses usually have have envelope outside capsid -HIV, flu - envelope allows virus to merge with membrane when entering and leaving host |
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Bacteriophage (DNA virus) |
Injects viral DNA into bacterium host cell; 2 effects on host cell: - bacteriophage produces new viruses, kills host and then infects surrounding cells - bacteriophage viral DNA incorporated into host DNA; host lives: - virus DNA replicated with bacteria DNA as host divides (all resulting new bacteria cells contain viral DNA - bacteriophage infection makes non pathogenic bacteria disease causing bacteria to produce virus toxins that cause disease symptoms (cholera, botulism) |
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RNA Virus |
enzyme: RNA replicase; copies viral RNA into more viral RNA - no DNA and no transcription: genetic info already in RNA form Viral recombination: combines RNA from human, pig and/ or bird flu strains; creates new flu strains - H3N2: human, H1N1: pig Respiratory infection: often followed by secondary bacterial infections; pneumonia - influenza spread by respiratory droplets and fomites (contaminated objects) |
influenza |
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Retrovirus |
2 RNA stands Enzyme: reverse transcriptase - copies RNA into DNA |
HIV |
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HIV (Human Immunodeficiency Virus) |
Causes AIDS (Acquired Immunodeficiency Syndrome) HIV binds CD4 receptors on T helper cells and macrophages - virus DNA inserts into host DNA Eventually T helper count declines- indicates onset of AIDS phase of illness HIV destroys the immune system - death results from secondary infections by opportunistic agents or unusual cancers (tuberculosis) |
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Treatments for HIV |
HAART: highly active antiretroviral therapy - drug cocktails: provide at least 2 different effects - reduce virus count to low levels - maintain T helper cell number to improve immune function - reduce resistance of viruses to treatment |
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Treatment targets on HIV |
Interfere with reverse transcriptase to inhibit DNA formation from RNA - AZT mimics thymine nucleotides - can produce non functional DNA Prevent virus entry through host membrane Prevent HIV DNA from inserting into host DNA Block virus assembly |
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Hepatitis Virus |
Many strains, syndromes, outcomes; all target liver Hepatitis A: infectious hep; vaccine - fecal/ oral transmission - contagious before symptoms appear Hep. B: Chronic hepatitis; liver cancer - vaccine - transmission similar to HIV - infected blood, IV drug abuse, unsafe sex, unknown causes Hep. C: higher fatality rate than HIV; no vaccine - symptoms appear 20 years after initial infection - infected for life - infected blood, IV needles, unsafe sex - about 50% of cases undetermined - main reason for liver transplants |
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Other Virus Diseases |
Polio: inhibits skeletal muscles - fecal/ oral transmission - Salk and Sabin vaccines eliminated polio from US Rabies: mammal reservoir; infects brain - transmitted in saliva through bites - travels through spinal column to brain - hydrophobia: fear of water HPV: many strains; cause most cervical cancers/ - spread through body fluids - incurable west nile virus: bird reservoir - mosquito vector for west nile virus - transfers from one host to another Ebola: fruit bat reservoir |
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Viroids |
Infectious RNA molecules smaller than viruses - only infect plants - potato spindle tuber - no documented viroid caused human infections at this time |
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Prions |
infections proteins that infect the brain prions are a misfolded form of normal brain protein - convert normal proteins in brain to prions infection usually acquired from eating meat contaminated with nervous tissue - usually slow acting with a long incubation time - not destroyed by high heat during normal cooking Examples: - scrapies: sheep; most infective - bovine spongiform encephalopathy (mad cow disease) - creutzfeldt Jacob disease: human prion disease similar to mad cow - acquired from eating prion infected beef - some people have genes for this disease - Kuru (related to cannabalism in New Guinnea) - chronic wasting disease (deer and elk) - a few reports from w texas |
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