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BIOL4 Biology Unit 4 Exam - 13th June 2011 watch

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    (Original post by User12399)
    Advantages of Artificial

    Fast action
    Components known
    Easy to store/apply
    Can apply with light machinery
    High nutrient content

    Disadvantages

    Can cost quiet a bit

    Natural

    Advantages

    Cheap

    Disadvtages

    Very soluble
    Can effect water courses (leeching)

    erm did you say natural fertilisers are very soluble and can be leached? this is not the case, as inorganic fertilisers are the ones that are more susceptible to leaching, as they often include nitrates in their purest, most soluble form.
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    (Original post by User12399)
    succession came up in jan, it was 5 marks so it wont come up again.
    I don't know why but checking the past papers they seem to love succession questions. :ahee:
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    (Original post by User12399)
    don't know but i've +repped you couple of times today so its saying "Please rate some other members before rating this member again." lol

    I'm not bothered about rep just the fact i'm learning while helping others. best way to learn
    Ok
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    (Original post by SK-mar)
    erm did you say natural fertilisers are very soluble and can be leached? this is not the case, as inorganic fertilisers are the ones that are more susceptible to leaching, as they often include nitrates in their purest, most soluble form.
    are there any further advan/disadvan for natural fertilisers that you could add to that list?
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    Fab, thanks. Good luck y'all!! I really hate this board, you get stupidly low raw marks which correlate to high UMS, so there's no way of guessing how you did. Uggh.
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    (Original post by Tericon)
    are there any further advan/disadvan for natural fertilisers that you could add to that list?
    I would guess that natural fertilisers can be broken down in organisms therefore it doesn't build up along the food chain affecting rare species such as eagles.
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    (Original post by likedylaninthemovies)
    Fab, thanks. Good luck y'all!! I really hate this board, you get stupidly low raw marks which correlate to high UMS, so there's no way of guessing how you did. Uggh.
    well there is if u get 60% ur gettin an A lol
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    (Original post by Thisisj)
    hi, can some 1 help me with question 5b on the jan 11 paper.. i know that GP = NP + R but i cant get the answer that they want? help please
    Its not asking for NPP, so far this question just take the peak of the cruve at medium light intensity. So about 2.75
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    i swer inorganic fertilisers get leached away more easily as they have soluble nitrates?

    is that right
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    (Original post by SK-mar)
    erm did you say natural fertilisers are very soluble and can be leached? this is not the case, as inorganic fertilisers are the ones that are more susceptible to leaching, as they often include nitrates in their purest, most soluble form.
    my bad, updated. thanks
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    (Original post by kingsmod1)
    well there is if u get 60% ur gettin an A lol
    Or 52% in the June 2010 and get an A*
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    (Original post by Tericon)
    are there any further advan/disadvan for natural fertilisers that you could add to that list?

    heres what I can think of for both:

    natural fertilisers

    advantages:

    - Slow acting fertiliser so doesn't need to be applied as often. this saves time and money for farmers.
    - often cheaper to buy than inorganic fertilisers
    Disadvantages

    - Farmers don't know the components in natural fertiliser, so they may not contain the right balance of nutrients for a crop.
    - They smell (haha don't actually put this ) ....

    Inorganic fertilisers

    Advantages

    - Fast acting
    - Farmers know the components in inorganic fertilisers
    - Easily stored
    - Applied using low-bulk machinery (could link this with less fuel consumption if needed) ....

    Disadvantages

    - Nitrates can be easily leached into nearby water sources through rain or irrigation
    - They need to be applied more often than natural so costs farmer time and money
    - Too much can cause an imbalance of nutrients in the soil and can cause plants and crops to die



    there are probably other points but these are usually enough to get all the marks in a question of this type.
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    ????
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    doesnt it annoy u when u understand a particular concept on bio4 but the Q on it doesnt come up lol?

    and for chapter 8 guys

    how do u kno if the p or Q is squared or not?

    if it says allele frequency then u dont square it and just do 1 - wateva it puts?
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    (Original post by Jackbruce)
    Its not asking for NPP, so far this question just take the peak of the cruve at medium light intensity. So about 2.75
    im sorry , i still don't understand that
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    Could someone outline eutrophication for me(and for yourself as revision of course)

    What I got down here is;

    1. Leaching of inorganic fertiliser into lake/river
    2. Algae grows rapidly
    3. Algae die but there's so much of it that bacteria strive as they decompose the algae
    4. Bacteria use up oxygen in water, oxygen concentration decreases
    5. Fish and aerobic organisms die due to low oxygen concentration
    6. bacteria decompose detritus, reducing the oxygen concentration even more
    7. random thought 'anaerobic bacteria infest the water possibly?'


    (Original post by kingsmod1)
    doesnt it annoy u when u understand a particular concept on bio4 but the Q on it doesnt come up lol?

    and for chapter 8 guys

    how do u kno if the p or Q is squared or not?

    if it says allele frequency then u dont square it and just do 1 - wateva it puts?

    P+Q=1 In this case P and Q indicate allele frequency
    P^2+Q^2+2PQ=1 P and Q are the respective homozygous genes of the alleles and 2PQ is the heterozygous gene.
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    (Original post by kingsmod1)
    doesnt it annoy u when u understand a particular concept on bio4 but the Q on it doesnt come up lol?

    and for chapter 8 guys

    how do u kno if the p or Q is squared or not?

    if it says allele frequency then u dont square it and just do 1 - wateva it puts?
    If it asks about population or genotype then its p or q squared. Think it as the genotype/population have the alleles already and say R/r is your alleles. RR = p squared and rr = q squared.

    If it's asking about allele frequency its on about p + q = 1 and it is not squared.

    If they ask about genotype/populations its going to ask about heterozygous genotypes
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    (Original post by kingsmod1)
    doesnt it annoy u when u understand a particular concept on bio4 but the Q on it doesnt come up lol?

    and for chapter 8 guys

    how do u kno if the p or Q is squared or not?

    if it says allele frequency then u dont square it and just do 1 - wateva it puts?
    this has always confused me for hardy weinberg too but the way i try and do it is: .... if its referring to the genotype then its 'p^2' ..... if its referring to a single allele frequency then its just 'p'


    for example .... the frequency of the the 'a' allele in cats = 0.56 .... it would be be p=0.56, so q = 1-0.56 = 0.44 etc..

    another example, the frequency of blue cats in a population is 0.6 .... (earlier on in the question it tells you that 'A' is the allele for red cats which is dominant to 'a' which is the allele for blue) .... so you know that 0.6 refers to 'aa' homozygous recessive ... and so 0.6 = p^2


    hope this helps...
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    (Original post by Stratos)
    Could someone outline eutrophication for me(and for yourself as revision of course)

    What I got down here is;

    1. Leaching of inorganic fertiliser into lake/river
    2. Algae grows rapidly
    3. Algae die but there's so much of it that bacteria strive as they decompose the algae
    4. Bacteria use up oxygen in water, oxygen concentration decreases
    5. Fish and aerobic organisms die due to low oxygen concentration
    6. bacteria decompose detritus, reducing the oxygen concentration even more
    7. random thought 'anaerobic bacteria infest the water possibly?'
    2.5 The algae cover the surface of the water so no light penetrating. Plants underneath can't photosynthesise so no oxygen produced and they die.

    8 anaerobic bacteria produce toxins, water unsafe to drink as it causes inefficient oxygen transport in babies and has been linked to stomach cancer in humans.
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    (Original post by SK-mar)
    this has always confused me for hardy weinberg too but the way i try and do it is: .... if its referring to the genotype then its 'p^2' ..... if its referring to a single allele frequency then its just 'p'


    for example .... the frequency of the the 'a' allele in cats = 0.56 .... it would be be p=0.56, so q = 1-0.56 = 0.44 etc..

    another example, the frequency of blue cats in a population is 0.6 .... (earlier on in the question it tells you that 'A' is the allele for red cats which is dominant to 'a' which is the allele for blue) .... so you know that 0.6 refers to 'aa' homozygous recessive ... and so 0.6 = p^2


    hope this helps...
    hi can you please explain 5b on the jan 2011 paper pleaseeeeeeeeeeeeeeeeeeeeeee
 
 
 
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