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    THANKS That actually helped me out
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    Could you help me out with this question??
    Describe the events that follow pollination and how they lead to seed formation.
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    (Original post by Shaudi)
    Could you help me out with this question??
    Describe the events that follow pollination and how they lead to seed formation.
    Fertilisation:-
    -Pollen grain nucleus has to fuse with the nucleus of the ovum
    -Pollen grain grows a tube
    -The tube digests it's way through the style of the tissue and into the ovary
    -Here it goes around to the opening in an ovule
    -Tip of the tube dissolves
    -Pollen grain nucleus moves out of the tube and into the ovule
    -here it fertilises the ovum nucleus

    Seed formation:-
    -Zygote develops into an embryonic plant
    -Other contents of the ovule develop into cotyledons
    -Cotyledons are a food store for the young plant and helps in germination
    -Ovule wall becomes seed coat
    -Ovary wall becomes fruit coat
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    Thank youuuu so much :d
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    ****
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    (Original post by themightysandu)
    Lets just use pests resistance to pesticides

    All living creatures have variation - i.e. they are not all the same
    There is a Selection Pressure of the pesticide, and at random a mutation occurs in a pest which makes it resistant, they have a selective advantage, and won't be killed by the pesticide, therefore the non-resistant pests are at a selective disadvantage. These non-resistant pests die because of the pesticides, whereas the resistant pest can reproduce and produce many offspring which are resistant and then reproduce more. Therefore the population of the non-resistant decrease and the resistant increases. This is bad for humans because we can't use the pesticide. So for a while we stop using the pesticide, then the non resistant population increases. then we kill them again.
    In other areas, lets say a group of rabbits with short ears, which can't hear things well, are released into woods their selection pressure is not being able to hear their predators and get killed by them. some rabbits reproduce and a gene mutates so that the offspring have large ears, they can hear the predators when they are further away, so when the predators approach they run, but the other rabbits in other areas don't know this and get killed (please don't try to picture this, I am and it is very disturbing), therefore, you are left with mainly long-eared rabbits in that area. Then compare this to if we released the same type of rabbits into a field with no danger of predators, there will be no need to have big ears because nothing is hunting them.

    As Darwin concluded 'Survival of the fittest'
    and to fill your childish needs: What does Mufasa talk about - 'The Circle of life'

    If anyone can add, feel free to
    Thanks a lot! You are of great help!
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    (Original post by Shaudi)
    Thank youuuu so much :d
    Happy to help
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    Do you think anything on the eye will come up?
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    I dunno, but they might ask how the eye changes when viewing a dimly/ brightly lit distant/near object XD it's very typical of them to ask.
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    I'm absolutely ******** myself for this exam, do you think it will be an easy or hard paper, June 2015 paper last year was piss easy, I hope they have something similar to it
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    (Original post by themightysandu)
    What's everyone's weakest topic, maybe if someone finds someone else's weakest a stronger topic they can go through and try to explain?
    Cause you know... Revision while procrastinating


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    dont get what we need to know about fish farming
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    This question about the events after pollination that lead to seed formation.
    Is it okay to give an answer regarding double fertilisation
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    (Original post by hamza.sheikh)
    Hello! Can you tell me what are the things we are supposed to know about the structure of the urinary system, the nephrons and about ultrafiltration? I'm having a feeling that this is gonna come up. Btw can menstrual cycle come?
    Oh my gosh I though that too!! I also think reproduction in plants will come up. Almost certain
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    (Original post by Shaudi)
    I dunno, but they might ask how the eye changes when viewing a dimly/ brightly lit distant/near object XD it's very typical of them to ask.
    They won't ask that If you're doing edexcle. Thats on paper 2.
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    (Original post by Sarah sahara)
    Oh my gosh I though that too!! I also think reproduction in plants will come up. Almost certain
    The seed formation question came up on this year's January paper so I'm not entirely sure whether there'll be a question on this.
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    (Original post by dRaGoN2509)
    The seed formation question came up on this year's January paper so I'm not entirely sure whether there'll be a question on this.
    You never know they might spice things up.
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    Can you answer the 3, 4 and 5 mark questions with bullet points?
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    My teacher says it's better to answer in prose.

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    (Original post by waleed29)
    Do you gys mind sharing your bio and chem notes as i have been in hospital for 3 weeks
    http://www.biology-resources.com/bio...eriments2.html
    Hey!!! hope ur well now!! this is a site i used for experiments!!!
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    (Original post by maths_geek234)
    I'm absolutely ******** myself for this exam, do you think it will be an easy or hard paper, June 2015 paper last year was piss easy, I hope they have something similar to it
    same i hope to god omg
 
 
 
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