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90 Cards in this Set
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big bang theory |
most accepted theory of how the universe formed - 15 billion years ago -space debris collected due to gravity (at centralized point), kept colliding and lead to the massive explosion= big bang- debris hurdled outward- gravity collected chunks into planets, stars, etc. Earth formed 4.6 million years ago |
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early conditions |
surface -oceans of Lava -high degree of volcanic activity Atmosphere -very poisonous -consisted of H2, N2, CO2, and CO -very little O2 or H2O |
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Chemical evolution |
earth cooled-> collision with moon, orbits us, caused tilt (possible) ->land masses formed-> volcano at first, oceans became more water-based-> Larger atmospheric gases began to form- ammonia (NH3) and methane (CH4) Molecules of life- where did they come from? |
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Stanley miller |
Idea about where energy for life came from- 1953 Lightening experiment |
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stanley's experiment |
CH4+NH3+H20+H2 electric charge (lightning) created simple organic molecules |
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primordial soup |
oceans of water and simple organic molecules Hydrothermal vents- cracks in the ocean floor that release gases and lava |
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early cellular life |
life emerged 3.8 billion years ago (800 million years from creation) best classified as an Archaean closest living relatives are stomatolites |
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bio trivia |
there are on average 100 lightning strikes every second of every day |
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evidence of evolution Comparative anatomy |
Analogous structures- structures in different organisms that appear very different but serve the same function -wings butterfly vs bird Convergent evolution- took different evolution paths to get to the same function |
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Homologous structures |
structures in different organisms that appear similar but serve different functions arm of humans, fin of dolphin, wing of bat, wing of bird- bones look all the same, but serve different function |
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vestigial structures |
organs/structures that appear to serve no function Wisdom teeth, tail bone (coccyx), appendix, nictitating membrane in Humans Whales/snakes- pelvis/legs |
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comparative embryology |
vertebrate embryos look very similar at early stages of development |
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fossils |
physical evidence of ancient organisms similarities and differences with living organisms can indicate changes that have occured |
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Charles Darwin biographical info |
English Naturalist -to date, has proposed the single most important scientific theory -lasted one semester at med school; went to Cambridge afterwards, thought about being priest Voyage-> HMS Beagle, passenger at request of dad; became ships naturalist, Galapagos Islands- 13 species of finches- similar except for beak size and shape |
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bio trivia |
Charles Darwin held a degree from Cambridge university in theology |
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theories |
Artificial selection- Darwin used as a model for developing his ideas Natural selection- Darwin's mechanism for evolution; differential survival and reproduction of certain individuals in a population Survival of the fittest- to be biologically fit, you must survive and reproduce |
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Book |
On the Origin of Species Published in 1859 |
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Microevolution |
changes that occur within a population over a relatively short period of time |
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Macroevolution |
changes over long periods of time that result in new species |
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natural selection requires variation in the gene pool sources of variation |
mutations: random changes in the gene pool- driving force of evolution sexual reproduction- producing unique offspring |
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Genetic drift |
anything that deceases variation in a population the gene pool gets smaller |
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Missing links |
Evolutionary intermediates Archaeopteryx- "holy grail" of fossiles; link between birds and dinosaurs "Ida"- a possible link within the human lineage |
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Human evolution Misconceptions |
Myth-humans descended from modern apes Truth- humans share a common ancestor with modern apes; our lineage with chimps split 6mya Myth- human evolution is sequential and orderly Truth- there are many branches, most with dead ends |
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Trends in hominin evolution |
bipedalism- upright increase in brain size -tool use -language Change in face structure |
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Australopithecienes |
appeared 4 mya Lucy discovered in 1974 3-5 ft tall, bipedal (upright) may have led to... |
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homo representatives |
homo habilis "Handy man" 2.5 mya; first to make and use tools; possibly capable of limited speech Homo erectus- "upright man" up to 6ft tall; 1.6mya; used complex tools and possibly fire; first to migrate out of Africa |
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homo representatives 2 |
Homo Neanderthalis- appeared 200,000 ya; larger heavier body; one of closest relatives; first to bury dead, vanished 30,000 yrs ago homo sapiens- 130,000 yrs ago, |
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Ecological levels of organization |
population- community- ecosystem, biosphere Habitat- the region where an organism naturally lives Niche- the functional role of an organism |
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Ecological succession |
the natural changes in the species makeup of a community |
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Primary succession |
begin on sites that have never supported life (island) or after a major disturbance (volcano) substrate: rock->sand->dirt Plants: lichens/mosses->grasses->shrubs->trees |
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Pioneer species |
first organisms to colonize an area moss |
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climax community |
a stable successional stage that remains until a disturbance Forest/woodland -tall grass -desert |
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Secondary succession |
begins after a minor disturbance tornadoes, fires, hurricanes (soil in tact) |
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bio trivia |
Polar bears are the only living animal that hunt humans with regularity |
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energy flow food web |
a network of who eats whom in a community very complex |
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trophic level |
job description |
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producers |
secure energy from the sun Autotrophs Plants, algae, some bacteria |
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Herbivores |
feed mainly on producers (plants) primary consumers |
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carnivores |
feed mainly on herbivores secondary consumers |
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Omnivores |
feed on all trophic levels tertiary consumers |
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decomposers |
breakdown organic material (detritus) detritivores |
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efficiency of energy transfer |
only about 10% of the energy is transferred between trophic levels 90% is used by the organism or lost as heat and waste |
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Ecological pyramid |
based on biomass always more mass per producers as compared to next level up due to energy loss |
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biological magnification |
the tendency of a chemical to become more concentrated as it is passed through the food web |
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bio trivia |
the african animal that has killed more humans than any other is the Hippo |
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biogeochemical cycles |
the recycling of nutrients between living an d non-living entities |
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Water cycle |
hydrologic cycle |
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Precipitation |
water droplets condensing and falling to the earth snow, hail, sleet, rain |
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Evaportation |
water changing from a liquid to a gas |
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transpiration |
evaporation of water from plants |
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human impact |
deforestation- reduces transpiration More freshwater is used than replenished Desalination-turning saltwater to fresh |
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Carbon cycle |
3 ways that carbon is released from storage |
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Decomposition |
allows for C to be recycled (fungus bacteria) |
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erosion |
releases carbon from rock |
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combustion |
releases carbon as CO2 (burning anything) |
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human impact |
deforestation and burning fossil fuels increase CO2 in the atmosphere Global climate change Ocean acidification |
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Nitrogen cycle |
recycling is crucial since N is in short supply in living creatures |
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Nitrogen Fixation |
converting N gas into a usable form |
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Nitrification |
producing proteins/nucleic acids from the N-rich molecules |
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Denitrification |
release of N gas through decomposition |
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human impact |
N released from burning fossil fuels contributes to Acid rain, Pollution/smog |
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Phosphorous cycle |
No atmospheric form released by erosion from rock Crucial element for DNA and ATP |
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eutrophication human impact |
addition of a large amount of nutrients to a body of water Algal bloom-> depletes O2-> leads to a fish kill |
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Populations Dynamics |
populations size # of individuales contributing to the gene pool us 311 million Japan 128 million |
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populat5ion density |
# of individuales per given area us 84 ppl/m2 Japan 836 pp/m2 ppl/area= density |
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Population growth rate |
difference between the birth rate and death rate 2015 growth rate was 1% know how to calculate: birth-deaths=% if out of 100 14b-12d=2% 26b-29d=-3% |
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doubling time |
number of years needed to double the population size bigger pop, less time to double |
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bio trivia |
a cockroach can live without its head for 9 days (45 seconds for a human head to live after decapitation) cockroach has little brains all over body, starves to death, can still mate too |
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age structures |
the relative number of individuals by age expanding population- triangle wide base Stable population-somewhat rectangular Declining population- inverted triangle, with narrow base |
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Immigration |
movement into a population |
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Emigration |
movement out of a population |
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population growth patterns |
there are two models for population growth |
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exponential growth population growth rate continuously increases 2;9gen;1,024;9gen;524,288 produces a J shaped curve unrealistic |
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Logistic growth population size levels off at some point produces an S-shaped curve |
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Carrying capacity |
max # of organisms that can survive in a given environment number fluctuates around this capacity |
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biodiversity |
the number of species in an area and the abundance of each speices |
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importance |
genetic diversity genetic warehouse, provides variety required of natural selection Medicines, 25% of all known drugs come from tropical plants Ecosystems functions, filter air and water, enrich soil, pollinate plants, etc Jenga effect |
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Habitat destruction |
reasons, create living space, economic development by 2040, virgin tropical rainforest will be gone, including up to 25% of all living species |
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overexploitations |
reduces number and genetic diversity overfishing is a top concern |
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alien species |
speicies that are not native to the ecosystem no natural predators redneck fishing tournament |
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bio trivia |
HUMAN tapeworms can grow up to 75 feet in length |
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Environmental resistance |
factor that prevents exponential growth |
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density-independent factors |
weather patterns and disasters fires geologic activity habitat destruction |
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Density- dependent factos |
lack of resources; food water shelter Disease predation |
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human impacts on earth's carrying capacity ecological footprint |
the amount of land/water needed to support a population reflection of lifestyle |
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agriculture |
"Green revolution" 1970's and 1980's- ability to grow crops worldwide crop production increased dramatically why- more crops, price drop, more crops, price drops again. better crops, better soil, less family farms Requires 100X more energy than traditional farming methods |
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resource availability |
desertification- the transformation of farm and grazing land into desert caused by over-farming and erosion Deforestation Over fishing Water shortage |
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Pollution |
Water- sewage, oil, fertilizer, pesticides Air- Ozone (O3) low level -> pollutant High level -> blocks harmful radiation from the sun |
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global climate change |
average global temp has increased 0.74 C in the past 100 yrs appears to be linked to increase in greenhouse gasses (CO2) could cause... sea level to rise; coastal flooding; extreme weather phenomena; climate change |
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carbon footprint |
the amount of CO2 entering the atmosphere due to one's lifestyle how to reduce footprint- recycling, away from plastic bags |