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BIOL4 Biology Unit 4 Exam - 13th June 2011 watch

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    You know a quadrat is basically a big square frame made up of many grids. Some of the squares will be completely covered with grass, others will be half and so on. But grass is continuous so sometimes it might be present in two squares so which one do you count? Does that make sense?
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    (Original post by FatalError)
    You know a quadrat is basically a big square frame made up of many grids. Some of the squares will be completely covered with grass, others will be half and so on. But grass is continuous so sometimes it might be present in two squares so which one do you count? Does that make sense?
    Yes it does thank you.
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    HSW is going to be so hard. I'm dreading this! Do you have any techniques when answering questions and are you resitting?
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    (Original post by FatalError)
    HSW is going to be so hard. I'm dreading this! Do you have any techniques when answering questions and are you resitting?
    Lol Im not resitting. I absolutely dread the HSW. My technique is to write partially illegible and only legibly when indicating key words - thats prob gonna be my tactic for the HSW questions :lol:
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    LOOOOOOL. Good luck man that might work, i'm going to try it. I failed the Jan paper but it was the easiest of the lot. I hope June 11 is a good paper. Alot of people complained about the Jan 10 paper because it was irrelevant to the spec.
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    Do plants lose any energy as heat?
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    Do plants lose any energy as heat?
    I don't think they maintain body temperature lol could be wrong though. They need ATP in protein synthesis, cell division active transport though.
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    (Original post by arvin_infinity)
    Describe and explain : integrated post-control system

    5 marks
    - integrated pest control systems are ones that make use of both chemical pesticides and biological agents for use in pest control
    - sometimes the combination for both can be more effective than just one or the other
    - it is also cheaper for the farmer if he was otherwise using just chemical pesticides
    - less time consuming as he can use biological agents which are self sustainable if he was otherwise using chemical pesticides only



    i cant really think of any other points except listing the advantages of either chemical pesticides or biological agents?
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    I came across a question:

    "Another gene has give aleles. How many different diploid genotypes are possible with five alleles?"

    The answer's 15. How?
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    (Original post by Fearsmoker)
    I came across a question:

    "Another gene has give aleles. How many different diploid genotypes are possible with five alleles?"

    The answer's 15. How?
    Imagine the five alleles are A,B,C,D,E

    Possible diploid genotypes:

    AA, AB, AC, AD, AE
    BB, BC, BD, BE
    CC, CD, CE
    DD, CE
    EE
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    (Original post by Jing_jing)
    Imagine the five alleles are A,B,C,D,E

    Possible diploid genotypes:

    AA, AB, AC, AD, AE
    BB, BC, BD, BE
    CC, CD, CE
    DD, CE
    EE
    Okay i get that now, thanks a lot
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    (Original post by Fearsmoker)
    I came across a question:

    "Another gene has give aleles. How many different diploid genotypes are possible with five alleles?"

    The answer's 15. How?
    five alleles for one gene means you can have AA,AB,AC,AD,AE,BB,BC,BD,BE,CC,CD ,CE,DD,DE,EE

    edit; seems I'm a bit late.

    Anyway enough revision for me today, going to revise genetics and photosynthesis tomorrow morning and that's unit 4 done.
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    (Original post by Fearsmoker)
    I came across a question:

    "Another gene has give aleles. How many different diploid genotypes are possible with five alleles?"

    The answer's 15. How?
    Think about it like this. Take the first allele, this can be paired with any of the 5 other alleles for a unique genotype. Taking the second allele, we can also pair it with all 5 other alleles. However one of these pairings is a repeat from the first 5. So we add four unique pairings. We can then apply the same logic to the other 3 alleles to get 3, 2 and 1 unique pairings in these cases. SO our total is 5 + 4 + 3 + 2 + 1 = 15


    if you know this notation for maths it is the same as 6C2. And in fact this generalises to (n+1)C2 for any n different alleles forming a diploid genotype.
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    Can someone also explain to me why the number '0.05' is important? Or isn't it? I've heard it come up now and again and i just don't know the significance of it? Any help on this would be much appreciated.
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    Whats intergrated pest control?
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    (Original post by Fearsmoker)
    Can someone also explain to me why the number '0.05' is important? Or isn't it? I've heard it come up now and again and i just don't know the significance of it? Any help on this would be much appreciated.
    When talking about a statistical test with significance (p = 0.05) means that the probability that the results being down to chance is 0.05 (or 5%) 0.05 is used as an accepted confidence limit in statistics, but you don;t need to know why for the purpose of this exam.
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    (Original post by Fearsmoker)
    Can someone also explain to me why the number '0.05' is important? Or isn't it? I've heard it come up now and again and i just don't know the significance of it? Any help on this would be much appreciated.
    It means a 5% probability of chance is allowed for the results to be significant. If the probability of it being due to chance exceeds this boundary the results are no longer significant and the null hypothesis is correct.
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    (Original post by SK-mar)
    - integrated pest control systems are ones that make use of both chemical pesticides and biological agents for use in pest control
    - sometimes the combination for both can be more effective than just one or the other
    - it is also cheaper for the farmer if he was otherwise using just chemical pesticides
    - less time consuming as he can use biological agents which are self sustainable if he was otherwise using chemical pesticides only



    i cant really think of any other points except listing the advantages of either chemical pesticides or biological agents?
    Im not so sure about that. The AQA book kinda defines it as using bilogical and chemical control as a last resort after changing the environment to make it more suitable for the crop
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    (Original post by SK-mar)
    - integrated pest control systems are ones that make use of both chemical pesticides and biological agents for use in pest control
    - sometimes the combination for both can be more effective than just one or the other
    - it is also cheaper for the farmer if he was otherwise using just chemical pesticides
    - less time consuming as he can use biological agents which are self sustainable if he was otherwise using chemical pesticides only



    i cant really think of any other points except listing the advantages of either chemical pesticides or biological agents?
    Found it ..its on page 77 t-book

    Define
    Conservation:
    Niche:
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    (Original post by Rickesh)
    Whats intergrated pest control?
    Modern intensive farming recognises the environmental dangers of the untrammelled use of pesticides, so is
    adopting Integrated Pest Management (IPM). IPM attempts to bring together all forms of pest management
    to benefit from the best of each. The aim is to reduce the effect of pesticides on the environment but
    without compromising the goal of maximising crop yield. There are 4 stages, each one more powerful than
    the one before:
    1. Identify the pests and their population density at which they cause economic harm – the economic
    threshold. Only take action against the pest if its population is above the threshold.
    2. Use suitable cultural methods to prevent pests reaching their threshold.
    3. If the pest population starts to exceed threshold the use biological control to bring it down.
    4. If biological control doesn’t work then use chemical pesticides, but at low and carefully controlled dose,
    and at the best time of year to minimise damage to other organisms while maximising effect on pest.
    5. At each stage the effect of that treatment is evaluated before deciding to proceed to the next stage.
 
 
 
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