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    (Original post by Kurraiyo)
    No interphase is NOT a stage in mitosis. Mitosis begins with prophase.
    thanks
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    (Original post by justanotherindigo)
    Thanks a lot!



    I know I hope that this paper isn't as bad!
    I think I'll redo that paper but I remember it being rather hard

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    (Original post by StUdEnTIGCSE)
    Do we need to know it?Posted from TSR Mobile
    I thought we have to :/
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    (Original post by Tha Realest)
    On page 36 of this thread ... There is a link and then go to page 109 in the booklet for the unit 2 mark scheme.

    ~ Good Luck :cool:
    i appreciate
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    can someone explain the difference in reliability and validity? i always get confused

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    (Original post by Rubyturner94)
    can someone explain the difference in reliability and validity? i always get confused

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    1) Reliability refers to the confidence we can place on the measuring instrument to give us the same numeric value when the measurement is repeated on the same object.

    Reliability refers to how consistent a measuring device is.


    2) Validity
    on the other hand means that our measuring instrument actually measures the property it is supposed to measure.

    Validity This refers to whether a study measures or examines what it claims to measure or examine.
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    (Original post by Tha Realest)
    1) Reliability refers to the confidence we can place on the measuring instrument to give us the same numeric value when the measurement is repeated on the same object.

    Reliability refers to how consistent a measuring device is.


    2) Validity
    on the other hand means that our measuring instrument actually measures the property it is supposed to measure.

    Validity This refers to whether a study measures or examines what it claims to measure or examine.
    thanks
    for one question it says why are all the seeds kept at same temperature? in the mark scheme it stated that temperature is a variable, needs to be controlled to ensure results are reliable.
    in another question it says why are seeds taken from the same plant? mark sheme says reduces genetic variation to ensure results are valid.
    i would have also put valid for first queestion but would have not got that mark, i dont get why its different in thia case?
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    I have actually only started revision 3 days ago, but im surprised how well it is going. Notes here are fantastic, they help alot.
    I have done 3 Past Papers so far. In the first one i had 55/80, second one 63/80. and third one 65/80. So i am improving and its going great. Kinda getting the technique to answer these questions and alot of questions in papers are repetitive imo. How are you guys going with PP's how are you scoring?
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    (Original post by Rubyturner94)
    thanks
    for one question it says why are all the seeds kept at same temperature? in the mark scheme it stated that temperature is a variable, needs to be controlled to ensure results are reliable.
    in another question it says why are seeds taken from the same plant? mark sheme says reduces genetic variation to ensure results are valid.
    i would have also put valid for first queestion but would have not got that mark, i dont get why its different in thia case?
    Validity refers to the technique and apparatus used for collecting the data .
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    (Original post by gimme those exams)
    I have actually only started revision 3 days ago, but im surprised how well it is going. Notes here are fantastic, they help alot.
    I have done 3 Past Papers so far. In the first one i had 55/80, second one 63/80. and third one 65/80. So i am improving and its going great. Kinda getting the technique to answer these questions and alot of questions in papers are repetitive imo. How are you guys going with PP's how are you scoring?
    just did the june 2009 i got full marks, but i cant come to terms with it lol i think i marked myself too nicely.
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    (Original post by Tha Realest)
    Validity refers to the technique and apparatus used for collecting the data .
    thanks
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    (Original post by Rubyturner94)
    thanks
    No problem ~ Your welcome
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    When a question asks you to describe the relationship between 2 things, mark scheme awards a mark for manipulating data, how do i correctly manipulate the data.

    January 2011, question 2b)iv) For this question i have stated the overall trend (There is positive correlation between the two things), then i have said that at 400mg it is 6 units and at 800mg it is 12.5units, this is a difference of 6.5 units.
    Is this the correct way to manipulate data????
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    (Original post by vithusan40)
    When a question asks you to describe the relationship between 2 things, mark scheme awards a mark for manipulating data, how do i correctly manipulate the data.

    January 2011, question 2b)iv) For this question i have stated the overall trend (There is positive correlation between the two things), then i have said that at 400mg it is 6 units and at 800mg it is 12.5units, this is a difference of 6.5 units.
    Is this the correct way to manipulate data????
    In a simple answer yes you've manipulated the data to prove your point

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    (Original post by diggy)
    In a simple answer yes you've manipulated the data to prove your point

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    So whenever there is a question which asks to describe the data, i can take two numbers away???
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    Can someone please explain to me the plant cell wall structure in detail?
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    (Original post by mynameisntbobk)
    basically, tumour suppressor genes are responsible for telling the cell cycle to stop, so don't make new proteins, or divide. If the tumor supressor gene is faulty, it won't be able to carry it out it's function which is marking point 3. And if it's not able to control division, then you know the cell cycle will occur faster (in less time) as it won't have to stop ~ marking point 2. Because it's faster as a whole, mitosis is faster, and interphase will be faster (marking point 1), and finally, because the whole thing is happening so fast and uncontrollably, the cells aren't able to specialise, as they presumabely start to go through the cell cycle, as there's nothing to tell it not too..

    hope this helps, if not, let me know
    oh right i understand now...very helpful, thank you!
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    (Original post by vithusan40)
    So whenever there is a question which asks to describe the data, i can take two numbers away???
    No it has to prove your point such as a positive correlation

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    Name:  g1.JPG
Views: 202
Size:  50.3 KBCalculate the percentage of the cell cycle time spent in G1
    + i want u to explain to me the graph FULLY!! which is S phase, which is which .....like everything in the graph pleasee!:cry::cry:
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    nerves are starting to kick in

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