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    (Original post by Annaaix_)
    UPDATE: I HAVE SCREENSHOTS WOOOO

    However there's like over 50 of them and they're on my phone and omg gonna take forever to put on tsr.
    If you want them can you like inbox me on fb? I'm literally so lazy pls
    Search 'Anna Christophides' my profile picture is the same as my little avatar on here.
    Whoever u are idm, just inbox me be like ''homie i want the screenshots'' and i'll share:heart:
    Thank you SO MUCH, it really means a lot Appreciated
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    (Original post by Annaaix_)
    UPDATE: I HAVE SCREENSHOTS WOOOO

    However there's like over 50 of them and they're on my phone and omg gonna take forever to put on tsr.
    If you want them can you like inbox me on fb? I'm literally so lazy pls
    Search 'Anna Christophides' my profile picture is the same as my little avatar on here.
    Whoever u are idm, just inbox me be like ''homie i want the screenshots'' and i'll share:heart:


    thank you soo much !!!!!!!
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    (Original post by Annaaix_)
    UPDATE: I HAVE SCREENSHOTS WOOOO

    However there's like over 50 of them and they're on my phone and omg gonna take forever to put on tsr.
    If you want them can you like inbox me on fb? I'm literally so lazy pls
    Search 'Anna Christophides' my profile picture is the same as my little avatar on here.
    Whoever u are idm, just inbox me be like ''homie i want the screenshots'' and i'll share:heart:
    Thank you very much!!!! And best of luck for your exams


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    (Original post by PlayerBB)
    Ahhh Thank you so much, it sounds like a great way of divising time, I will definitely start trying it!!! Normally,I used to solve the first question, spend around 20 minutes on it then jump to the last question the go back to the second so I guess I have to change it because it's consuming so much time!! And I am the kinda nervous one so like i'll keep rechecking till time finishes!!

    By the way, on the question you have just posted before, I was solving this paper, for the table, the question didn't even say that we should calculate the mean so how i am supposed to know? (although I guess in the recent papers, they always specify when to calculate the mean)

    Sorry for asking a lot
    Yea this is the first paper so maybe they didn't. But I always calculate the mean unless they state that find the range or median or mode! So, as a general rule it's better to always calculate the mean 'cuz they wontt cut marks even if they didn't ask for it! There's no negative marking in edexcel
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    (Original post by Adorable98)
    I'm a bit confused with validity??
    Could anyone explain and give me a list of examples
    I just saw this post! Well, Validity is all about doing the experiment under the same conditions everytime..
    As in If you're doing the experiment of daphnia heart rate to see the effect of caffeine, you'd use the same daphnia, at the same temperature, in the same light intensity blah blah and you just alter the concentration of caffiene.
    Got it? x)
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    (Original post by Annaaix_)
    Summary notes for unit 6 bc I haven't found the thread for it

    when describing an experiment:
    -state dependent and independent variable and state how to measure the independent (dcpip, counting, measuring length, etc)
    -5 diff. values for dependent variable (e.g. temperature - 5, 10, 15, 20, 25 deg) and how to control (waterbath/incubator,etc)
    -refer to REPEATS.
    -try come up with a control
    -state a variable to keep constant for validity (usually source of organism or pre-treatment, or fruit from same source)

    writing null hypothesis:
    -''no significant correlation between (dependent) and (independent) variable
    OR
    -''no significant difference between (dependent) and (independent) variable
    -use correlation when comparing a range of values, use difference when comparing 2 diff values.

    detailed method of experiment (same as describing PLUS these):
    -mention time period (example: leave for 48 hours)
    -2 variables to control and how to keep them constant (this gives 4 marks so MAKE SURE YOU DO IT)
    -description eg. aseptic conditions

    when it asks to record, present and analyse data:
    -calculate the rate/growth/change
    -calculate means
    -draw table w/ headings and units
    -sketch graph w/ headings and units
    -say ''use spearmans rank to determine correlation''

    I have a question tho if anyone knows the answer.
    On some questions it says ''the student applied a t-test to explore significance blah blah blah, she obtained this result, the table below shows critical values for t-test calculations'' how the hell do u draw conclusions from that:cry2:
    Heyy, I just read these.. They're great but i just wanted to add a bit if you don't mind!
    In the record, present and analyse data question; When the experiment is to find optimum concentration of something (say optimum concentration of a mineral ion or optimum light intensity etc.) The first three marks are the same but the fourth mark isn't for some test like spearmann's, It's for stating "find the optimum concentration from the graph" instead.

    And in the Q#3(b)
    write these, Practice proposed method to see if it works.
    Consider any other variable that may be affecting the experiment and plan to control them.
    Select the suitable dependent variable (whatever it is for different experiments)
    Select the most suitable conditions for experiment (temp, light intensity etc.)
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    (Original post by bdoon esm)
    Thank you very much!!!! And best of luck for your exams


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    (Original post by Annaaix_)
    UPDATE: I HAVE SCREENSHOTS WOOOO

    However there's like over 50 of them and they're on my phone and omg gonna take forever to put on tsr.
    If you want them can you like inbox me on fb? I'm literally so lazy pls
    Search 'Anna Christophides' my profile picture is the same as my little avatar on here.
    Whoever u are idm, just inbox me be like ''homie i want the screenshots'' and i'll share:heart:
    Thanks to Annaaix! She is the best..lots of love..
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    (Original post by Rizwana78)
    Thank you soooo much!
    Let me try to answer your question though.
    You usually use significance level 0.05 (I.e 95% confidence level) and then you compare the student calculated t value with the critical value at 0.05, and then draw out a conclusion from that. If the students calculated value is higher than the critical value then you accept that there is a correlation in the two variables that you're investigating. (Eg: There is a significant correlation between the increase in conc of rennin and the rate of milk clotting; if there is a null hypothesis stated then you reject it and you have to mention this in the ans as well aaaaand you can also state if there is a positive or a negative correlation) if the student's calculated value is lower than the critical value then you state that there is no significant correlation between blah blah and you accept the null hypothesis (state null hypothesis only if it was asked in the question before) if asked, you have to give the biological explanation as well.
    Sometimes degrees of freedom is given and you have to choose in that case don't panic it's just the sample size.

    0.05 is the probability and 95% is its percentage.

    I hope it's clear to you now.
    I'm afraid you are not supposed to use the word "correlation' when it comes to t'test.
    The t-test is for finding whether there is a significant difference between two means.
    Hence,you say, "There is or isn't a significant DIFFERENCE between..."
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    (Original post by Sandy_Vega30)
    I'm afraid you are not supposed to use the word "correlation' when it comes to t'test.
    The t-test is for finding whether there is a significant difference between two means.
    Hence,you say, "There is or isn't a significant DIFFERENCE between..."
    Hello,

    So, do we only use the word 'correlation' for the Spearman's rank test then?
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    (Original post by user179)
    Hello,

    So, do we only use the word 'correlation' for the Spearman's rank test then?
    Yes! Definitely.
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    Alright then

    So, what are your predicitons for unit 6B guys?
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    I have a question if anyone could help me the first question 1a is always describing the experiment, what are some standard answers you should put? I find it's different for every paper, I can't figure out the pattern.
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    (Original post by Annaaix_)
    I have a question if anyone could help me the first question 1a is always describing the experiment, what are some standard answers you should put? I find it's different for every paper, I can't figure out the pattern.
    To write an experiment, you must use CORMS.
    C - control: always include a control in your experiment, eg for the light intensity leaf experiment have an empty test tube with just some indicator in it...
    O - organism: what organisms will be involved and what similarities do they need to have eg. same sex, age, health, ect
    R - repetition: how many repeats do you do to make it more practical?
    M - measurement: what do you plan to measure? eg growth length temperature weight size ect.
    S - standard: what do you need to keep the same? eg time, diet, oxygen, light intensities pH ect

    There is no other pattern because all experiments are different. But in order to plan an experiment? Bottom line, Use CORMS.
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    Not sure if it is an out of the blue question but do any of you have pdf version of the cgp biology revision guide? I know its not for our board but I heard it is quite helpful... I never interacted so much in any other thread so I asked here..
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    (Original post by user179)
    Alright then

    So, what are your predicitons for unit 6B guys?
    What about urs? You predicted anything?
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    (Original post by Sandy_Vega30)
    To write an experiment, you must use CORMS.
    C - control: always include a control in your experiment, eg for the light intensity leaf experiment have an empty test tube with just some indicator in it...
    O - organism: what organisms will be involved and what similarities do they need to have eg. same sex, age, health, ect
    R - repetition: how many repeats do you do to make it more practical?
    M - measurement: what do you plan to measure? eg growth length temperature weight size ect.
    S - standard: what do you need to keep the same? eg time, diet, oxygen, light intensities pH ect

    There is no other pattern because all experiments are different. But in order to plan an experiment? Bottom line, Use CORMS.
    Maynn this was so helpful.. Thanks ^______________^
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    (Original post by Quirky01)
    What about urs? You predicted anything?
    No, nothing to be honest. What about you?
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    (Original post by Annaaix_)
    I have a question if anyone could help me the first question 1a is always describing the experiment, what are some standard answers you should put? I find it's different for every paper, I can't figure out the pattern.
    I try starting it with mentioning dependent and independent variable.
    Then I write what needs to be kept same,
    followed by how do we measure dependent variable
    and then the conditions e.g temp or light or watever we know,
    write a control group for your experiment
    and end with stating repeats!
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    Out of A2 practicals gel electrophoresis seems to be important!
 
 
 
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