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BIOL4 Biology Unit 4 Exam - 13th June 2011 watch

  • View Poll Results: Are you resitting this unit?
    YES!
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    NO!
    46.04%

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    (Original post by Rickesh)
    Ribulose bisphosphase?? Something like that...
    It's not RuBP. The enzyme is used to join CO2 to RuBP.
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    (Original post by FatalError)
    What is the enzyme that fixes CO2 into the calvin cycle?
    Rubisco, which has 8 active sites! Just a fun fact there Also thought to be the most abundant enzyme in the world.
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    What is the difference between agricultural and natural ecosystems?
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    Ping pong answers are good because in January i remember 4 questions come up that people asked here. I still failed though, HSW messed me up!
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    (Original post by FatalError)
    Ping pong answers are good because in January i remember 4 questions come up that people asked here. I still failed though, HSW messed me up!
    What did you get?
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    What on conservation could come up, there's barely anything in the nelson thornes book on it.
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    Agricultural ecosystems have additional energy input in the form of fossil fuels for farming machinary and food for farmers themselves. Increase in productivity due to preventing limiting factors with the use use of additional nitrogen fertilizer. Reduced species diversity due to use of pesticides to control pest numbers and also plagioclimax so succession doesn't occur.
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    I got an E. I had C3 in the morning, Business Unit 3 straight after, 30 minutes break then Biology!
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    (Original post by FatalError)
    Agricultural ecosystems have additional energy input in the form of fossil fuels for farming machinary and food for farmers themselves. Increase in productivity due to preventing limiting factors with the use use of additional nitrogen fertilizer. Reduced species diversity due to use of pesticides to control pest numbers and also plagioclimax so succession doesn't occur.
    yep..your turn
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    What on conservation could come up, there's barely anything in the nelson thornes book on it.
    Just remember the types of land.

    Moorland- Basically succession prevented by burning and only heather survives (it's a plant species)
    Hedgerows- Just cutting so doesn't develop into forest.
    Grassland- Grazing. Remember that grass can still grow but not other plant species because grazing cuts their shoots off whereas grass auxin is produced at the base so it can still grow despite grazing.
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    Hi what are definitions for :

    gross productivity and net productivity.

    Note : I know what they are just want a typical aqa answer.
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    Why are hedgerows a disadvantage to farmers?
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    gross productivity and net productivity.
    Ermm, is gross productivity the amount of energy initially available and net productivity the amount of energy left over at the trophic level after respiratory losses?
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    (Original post by FatalError)
    Why are hedgerows a disadvantage to farmers?

    Takes up space that could be crops
    Makes turning machinery difficult
    Acts as habitats for pests.
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    (Original post by Black Butler)
    Hi what are definitions for :

    gross productivity and net productivity.

    Note : I know what they are just want a typical aqa answer.
    Gross productivity is the total amount of organic material produced whereas net productivity is the total increase in dry biomass after respiratory losses?

    I'm always a bit fuzzy on those two... and the majority of ecology
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    (Original post by FatalError)
    Why are hedgerows a disadvantage to farmers?
    Because they reduce crop yield, as the crops have competition (interspecific) e.g for nutrients such as nitrate ions this becomes the limiting factor and prevents photosynthesis from reaching its maximium. They also take up a lot of space therefore less space fpr the crops.
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    Takes up space that could be crops
    Makes turning machinery difficult
    Acts as habitats for pests.
    Yep that's it. Also remember that plant species in hedgerows will compete for nutrients and water in the soil and so could reduce crop productivity.
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    (Original post by Jing_jing)
    Gross productivity is the total amount of organic material produced whereas net productivity is the total increase in dry biomass after respiratory losses?

    I'm always a bit fuzzy on those two... and the majority of ecology
    Ive got it as the rate at which chemical energy (from biomass) is assimilated by the plant

    and for net productivity the same thing except an extra 'excluding respiratory losses'

    eh?
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    (Original post by Black Butler)
    Ive got it as the rate at which chemical energy (from biomass) is assimilated by the plant

    and for net productivity the same thing except an extra 'excluding respiratory losses'

    eh?
    They're pretty much the same thing, just the wording is different

    Basically Net=Gross - Respiratory losses
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    net productivity= the amount of energy left after respiration
    gross productivity is the rate at which plants assimilate the chemical energy
 
 
 
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