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    (Original post by Shertic)
    Does anybody remember the figures in the X^2 question?
    I don't know the figures but I got 1401 as the answer.
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    (Original post by WishIHadRevised)
    I don't know the figures but I got 1401 as the answer.
    I remember getting 1400 something but I'm not sure if I got 1401
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    (Original post by Miller_r)
    Yea i did explain what the auxin does but knowing how much detail they want in A2 i thought there may be extra marks explaining how it gets there
    There probably will be marks for it, if it's not in the 'main' mark scheme, it'll probably be in the AVP bit.
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    (Original post by WishIHadRevised)
    I don't know the figures but I got 1401 as the answer.
    I got that too but i feel like we forgot to do something that figure is way too high
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    (Original post by Miller_r)
    I got that too but i feel like we forgot to do something that figure is way too high
    Its right. The fact it was so high just shows that the cross was not down to chance at all. Even if you had to do something else to get a smaller number( which you wouldn't) you'd still get at least 2 out of 3 for calculations
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    (Original post by games211)
    lool ha what did you put?
    I still put mitosis and meiosis and Dna replication and cytokinesis but like I just didn't read it haha!!
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    (Original post by baymax96)
    I got 240 Ums last year. what do I need this year for an A/b
    To get an A overall you need 480 UMS out of 600

    so you need 480-240 = 240 ums this year for an A

    and you need 420 overall for a B so you would need 180 this year for a B
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    (Original post by ShivanjaliNP)
    Do you reckon for Q 1 you could the marks for Interphase and Telophase instead of DNA rep and cell division?
    I put interphase and telophase and some other people did too! I don't see why they wouldn't accept it - interphase is when all of the DNA replicates, so the amount of DNA doubles. Then telophase is when it all gets separated into two different cells - so theoretically halving the chromosomes. Don't see the problem!


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    (Original post by Lychees)
    Could I get marks for having talked about barriers that could also cause genetic variation in the 9 marker question on second page. Like geographical barriers etc
    I never even thought about that. You might do but the genetic variation observed would still be down to stuff like mutation and crossing over etc. The only reason you see new species arising is down to different selection pressures either side of the barrier.
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    omg i done that aswell!! cant remember the specific behaviours at all! do you think we could get one mark for it? LOL
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    (Original post by Boardy123)
    I never even thought about that. You might do but the genetic variation observed would still be down to stuff like mutation and crossing over etc. The only reason you see new species arising is down to different selection pressures either side of the barrier.
    For that i also put down how genetic variation could be caused by genetic engineering they never said it had to be natural right
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    What was the reason for the 1:1:1:1 ratio

    I said stuff about linkage :dontknow:

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    I'll go through my answers. Some will definitely be wrong but i wrote down everything I answered in the exam.
    1. Mitosis, Meiosisdna replication, anaphase.
    genetic variation: discussed crossing over at chiasma in Prophase 1, random mutations, random mating and random fusion of two gametes and independent assortment in metaphase 1 and 2 = random allele combinations

    2. Overall increase from first year of data to last, fluctuates throughout, data to support this
    Data reliable as its annually recorded? Irrelevant as its no reflection on pop size, illegal hunting my of occurred?
    Pop size: intra and inter comp for food, space,water etc. possible disease with date, illegal hunting and predation
    Wolves introduced to maintain biodiversity as elk pop. too high for carrying capacity of ecosystem

    3. the one marker was easy (just the code bit)
    I discussed the chain termination method and mentioned electrophoresis for the 4 marker but was very unsure.
    Bronchioles- loss of elasticity of smooth muscle due to tissue damage from excessive coughing?
    less force and pressure to push air out of lungs
    mutation causes change in nucleotide bases so receptor active site changed, loss of function, not complementary so can't bind
    other drug worked as may have receptors for it
    Invalid due to small test size= only 31 kids on each drug
    i put nuclear DNA for saliva but thats 100% wrong

    4. geographical isolation, genetic drift
    C because greater frequency of alleles changed and smaller population
    Chi- 1401, reject Perhaps due to episatis or some sort of linkage (sex?)

    5. Bomb calorimeter burn organisms in oxygen, calc wet-dry mass, NPP, Not all plant digested
    FEBADC
    Reflex, habituation,taxis,insight,imprin ting
    Both release specific hormones in times of stress and both go to target cellsplants-
    mitosis, veg propagation of suckers, haploid in gametes diploid in plant tissue but idk
    polyploidy question? larger cells, more offspring

    Positive phototropism, auxin distribution, cell elongation turgid cells = bend to light
    human- innate behaviour, automatic reflex to move to prevent damage to body
    all i got for cell death was that they might burst,and oxygen deprivation in 2nd one
    said anticoagulant type treatment may increase blood viscosity causing even higher blood pressure

    cerebrum and cerebellum involved, neurones can't transit action potentials?
    disadvantage as reproduction rates decrease, high nicotine means less seeds. nicotine no advantage to plant?
    postsynaptic membranenicotine q can't really remember- talked about complementary and same shape, bind instead of acetylcholine, less transmission of messages, no standby return
    diffuse through xylem in vascular bundle
    we have enzymes to break down substance ?
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    That paper was so weird. Here's a video to cheer you guys up: https://www.youtube.com/watch?v=V64jcKu0XHU
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    (Original post by doctor_2_be)
    What seed???
    cress seed
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    (Original post by Boardy123)
    I never even thought about that. You might do but the genetic variation observed would still be down to stuff like mutation and crossing over etc. The only reason you see new species arising is down to different selection pressures either side of the barrier.
    If this is the big marker, didn't it say during nuclear division or something though?
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    (Original post by EvasiveRose)
    That paper was so weird. Here's a video to cheer you guys up: https://www.youtube.com/watch?v=V64jcKu0XHU
    Hang myself with a line transect lol
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    (Original post by Lizzieee4)
    If this is the big marker, didn't it say during nuclear division or something though?
    It said to make reference to it but not the whole thing who knows with ocr marks anyway
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    (Original post by JoshFH)
    I think it was just trying to show that there was twice as much genetic information after replication. So it started at two, jumped to 4, came back down to 2 then went to 1. So if you use those numbers but instead think of chromosomes you have your normal cell, it undergo's DNA Replication, forms two sets of chromosomes, cell fission occurs and it goes back to normal number of chromosomes, then divides again and this takes it down to one.
    That actually makes a lot of sense, looking back. I didn't think of that during the exam.
    Thank you.
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    (Original post by Lizzieee4)
    If this is the big marker, didn't it say during nuclear division or something though?
    crossing over does occur during cell division...
 
 
 
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