eco 1

  1. Define species
    Species: group o organisms tt can interbreed and produce fertile offspring e.g. lion
  2. habitat
    Habitat: environment in which species normally lives or location o living organism e.g. wetlands
  3. population
    Population: group o organisms o same species who live in same area at same time e.g. population of mice
  4. community
    Community: group o populations living and interacting with each other in an area e.g. deer, owls, and bears living in the same area of a forest
  5. ecosystem
    Ecosystem: community and its abiotic environment e.g. fresh hydro ecosystem
  6. ecology
    Ecology: study o relationships b/twn living organisms and b/twn organisms and their environment e.g.
  7. Distinguish between autotroph and heterotroph
    • e.g.  autotroph -> algae
    • heterotroph -> human/cat/dog etc
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  8. Distinguish between consumers, detritivores and saprotrophs.
    • e.g. consumers: lion
    • detritivores: earthworms
    • saprophytes: yeast
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  9. Describe what is meant by a food chain, giving 3 e.g., each with at least three linkages (four organisms)
    • food chain shows the linear flow /direction of energy flow from one species to another.
    • E.g. an arrow from A to B means that A is being eaten by B = indicates the direction of the energy flow.
  10. 3 examples
    • producer (1) / primary consumer (2) / secondary consumer (3) / tertiary consumer (4)
    • carrot plant--->eastern cottontail rabbit--->red fox ---> golden eagle
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    • Bushgrass---> Impala ---> Cheetah----> Lion
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    • buckwheat ---> Gopher ---> Gopher snake ----> Red Tailed Kite
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  11. Describe what is meant by a food web
    • Shows complex interactions between species within a community/ ecosystems
    • shows all the feeding relationships in a community with arrows which show the direction of the energy flow
  12. Define trophic level
    Trophic level: the trophic level of an organism is its position in the food chain. 

    Producers, primary consumers, secondary consumers and tertiary consumers are examples of trophic levels.

    • defines the feeding relationship of that organism to other organisms in a food.
    • note: some animals may be more than one trophic level depending on differing food chains e.g. could be 3 or 4
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  13. light is
    light is the initial energy source for almost all communities
  14. Explain the energy flow in a food chain
    • energy losses b/twn trophic levels include material not consumed or material not assimilated + heat loss bc cell respir
    • Producers get energy fr sun (light) of photosynthesis.
    • Energy flows from producers to primary consumers, to secondary consumers, to tertiary consumers..
    • Energy is lost between trophic levels in the form of heat through cell respiration, feces, tissue loss and death.
    • Some of this lost energy is used by detritivores and saprotrophs.
    • also lose energy in the form of heat through cell respiration.
  15. energy transformations
    are never 100% efficient
  16. Explain reasons for the shape of pyramids of energy
    • Pyramid shows flow energy fr one trophic lvl to next in community·
    • Units are energy per unit area per unit time, kJ m-2 yr-1·
    • model shows the typical loss of energy from solar radiation through the various trophic levels·
    • causes a tapering of the model·
    • narrowing shape illustrates the gradual loss of energy progressing along the links of a food chain to higher tropic levels·
    • e.g. lots of protozoa, less mosquito larvae, less carp, few pike
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  17. Explain that energy enters and leaves ecosystems, but nutrients must be recycled.
    • energy enters and leaves ecosystems but nutrients must be recycled·
    • Energy is not recycled.
    • Constantly being supplied to the ecosystem through light energy fr sun
    • Energy is lost from the ecosystem in the form of heat through cell respiration./ lost in feces, tissue loss and heat·
    • Nutrients must be recycled as there is only a limited supply of them. ·
    • They are absorbed by the environment, used by organisms, recycled and then returned to the environment.
    • Producers (autotrophs) take inorganic molecules and convert them to organic compounds.
    • consumers take in, upon death, recycled by saprotrophic bacteria and fungi (decomposers) for nutrients
    • e.g. nutrients like  Carbon, nitrogen and phosphorus
  18. saprotrophic bacteria and fungi (decomposers)
    Saprotrophic bacteria and fungi recycle nutrients (organic molecules) of dead organisms
  19. Draw and label a diagram of the carbon cycle to show the processes involved
    (interaction living organis and biosphere through photosyn, cell resp, fossilization, combustion)
    size arrows important
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  20. details carbon cycle ***
    • Photosynthesis by terrestrial plants and algae (freshwater and oceans) in which atmospheric (and dissolved ) carbon dioxide is removed and fixed as organic compounds such as carbohydrate, lipid and protein.
    • Respiration by all organisms in which they metabolise organic molecules releasing carbon dioxide.
    • Feeding, in which the carbon of organic molecules is move from one link in the food chain to another.
    • Fossilization in which carbon as organic molecules becomes trapped in sediment as coal. gas and oil.
    • Combustion during the burning of fossil fuels and burning of biomass.
  21. Analyse the changes in concentration of atmospheric carbon dioxide using historical records
    • atmospheric co2 monitored at mauna loa observatory (MLO) since 1958
    •  trends in atmospheric gases are studied as indicators of potential climate change(greenhouse gases)
    • annual variation in co2 levels (peaks early spring after winter = least photosyn, lowest late fall after summer greatest photosyn) = seasonal variations co2 by land plants, partic northern hemisphere forests 
    • overall upward trend increase in co2 since 1958
    • prior 1880, atmospheric co2 pret constant
    • incre at 2 ppm
Card Set
eco 1
eco 1