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    (Original post by Aimen.)
    The newer papers as in these IAL ones give medians and range as well. And they even gave this chi-squared test aswell!
    Yeah!!!!

    By the way, what experiment are you predicting ? Since there is no trend at all, any experiment might come up but there is a very low possibility of repeating the experiment more than twice right
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    (Original post by Adorable98)
    Does anyone know how to predict what sort of question would come up in 1(c) ??
    Since it depends on the experiment and we can't even predict the experiment, I guess that's very hard to tell
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    (Original post by PlayerBB)
    Since it depends on the experiment and we can't even predict the experiment, I guess that's very hard to tell
    So basically Question 1 (c) should always be related to the experiment given in question 1 (a)?
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    (Original post by Polpi)
    https://www.youtube.com/channel/UCoX...WiEdoVA/videos



    this has all the experiments AS TO A2
    Thank you so much 😁
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    (Original post by Aimen.)
    Can someone please tell me that when you're doing pcr experiment, do you add primers and nucleotides at the begining of after step 1 in which DNA strands seperate???
    Ok what variables should be controlled in gel electrophoresis if it comes? How should it be controlled?
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    (Original post by dinithisara)
    Thank you so much 😁
    Wow nice one!
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    Exaplain this to me please.. This is from jan 14 question 1(d)(ii) unit 6
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    June 13 Q1(b)(ii) - Mp2 says increase in temp would decrease breathing rate but why? Shouldn't it increase?
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    (Original post by Quirky01)
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    Exaplain this to me please.. This is from jan 14 question 1(d)(ii) unit 6
    A DNA strand consists of many genes that code for specific amino acids right?
    So the scientist decided to examine ONLY 5 genes that are different from each other.
    I hope that makes sense.
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    June 2015, the detailed method tests the hypothesis that the longer the vegetables are kept warm after cooking, the lower their vitamin C content is.
    Has anyone got the answer for that? Please share it, I'd be grateful x
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    (Original post by Sandy_Vega30)
    A DNA strand consists of many genes that code for specific amino acids right?
    So the scientist decided to examine ONLY 5 genes that are different from each other.
    I hope that makes sense.
    Well thanks but i think mark scheme says sth different...not sure
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    (Original post by user179)
    June 2015, the detailed method tests the hypothesis that the longer the vegetables are kept warm after cooking, the lower their vitamin C content is.
    Has anyone got the answer for that? Please share it, I'd be grateful x
    You follow the procedure for measuring the Vitamin C content by using DCPIP indicator.
    First, you take Vitamin C solution of known concentration and add it using a pipette to the same volume of DCPIP (say 2cm^3) you will use for the duration of the experiment. Find out the volume required to decolourise the DCPIP.
    Next, you cook the vegetable, keep them warm and you may either crush or blend the vegetables and obtain the extracts.
    Independent variable would be the length of time food is stored after cooking.
    Then include what times you're going to use like 0 minutes (which would mean as soon as it was cooked), 3 minutes, 6 minutes, 9 minutes and 12 minutes (you can use your own time intervals)
    Dependent variable would be the Vitamin C concentration
    So as the procedure states, you take a known volume of DCPIP solution (2cm^3) in a measuring cylinder and you add drop by drop of the veggie extract with a pipette, recording the volume required to decolourise the DCPIP at each time interval.
    You write about two other variables that would affect the result and how you would control them.
    Repeat several times.
    Finally, you can find the Vitamin C concentration of the cooked vegetables at each time period by using the formula
    Concentration=
    (conc of Vitamin C used x Vol. of Vitamin C used) /Volume of veggie extract used


    Here's the markscheme
    https://3ef7e8cb3a958922c328db7b6aaf...%20Biology.pdf
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    (Original post by Quirky01)
    Ok what variables should be controlled in gel electrophoresis if it comes? How should it be controlled?
    A friend shared this link. It's very helpful. Check it out
    http://biology-a2.weebly.com/unit-6.html
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    I just figured out that for Spearsmann rank correlation test we plot a scatter grraph or line graph.. And for t-test or mann-whitney u test we plot a bar graph.. Isn't it correct??
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    (Original post by notsoclueless)
    A friend shared this link. It's very helpful. Check it out
    http://biology-a2.weebly.com/unit-6.html
    That actually is very helpful. Thanks x
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    (Original post by Aimen.)
    That actually is very helpful. Thanks x
    No problem ^_^
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    Okay so I've seen alot of people around here wanting to know the predictions for June 2016 paper, although I'm not a paper-setter so I can't be very certain but here's what I came up with
    AS practicals:
    1.Effect of caffeine on heart rate of daphnia- Jan 2012(Q#2)
    2.Vitamin C content of fruit juices- Jan 2013 and June 2015
    3.Effect of temperature on permeability of membranes-June 2010
    4.Enzyme concentration and rate of reaction-Jan 2011,Jan 2015 and Jan 2013
    5.Observing mitosis-Jan 2016
    6.Totipotency and plant tissue culture-(never)
    7.Tensile strength and plant fibres-(never)
    8.Investigating plant mineral deficiencies- June 2013/ Specimen paper IAL
    9.Antimicrobial properties of plants-Jan 2014

    A2 core practicals:
    1.Looking for pattern (ecological studies)- June 2010, Jan 2011 and June 2012
    2.Effect of temperature on hatching rate of brine shrimps/germination- June 2011
    3.DNA Gel Electrophoresis-(NEVER)
    4.PCR- Jan 2014
    5.Effectiveness of antibiotics- Jan 2011, June 2012 and June 2015
    6.Measuring rate of oxygen uptake- Jan 2012, Spoecimen paper GCE and Jan 2015
    7.Investigating breathing- June 2013
    8.Can Snails become habituated to a stimulus?- June 2014

    Well, so the expected topics for this paper (the ones that have never showed up earlier are Electrophoresis, Totipotency and tensile strength).One of them is definately gonna show up!
    But please don't kill me if it doesn't! I'm just as clueless as you people hehe
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    (Original post by Aimen.)
    I just figured out that for Spearsmann rank correlation test we plot a scatter grraph or line graph.. And for t-test or mann-whitney u test we plot a bar graph.. Isn't it correct??
    Yep that's correct! Spearman's Rank tests for correlation within a range and plotting anything with a range of values would be plotted with a line graph or scatter graph (although line is better). T-test and Mann-Whitney are used more for differences between two or more variables, so like testing vit C content in multiple foods, testing males against females, or testing 2 different fields, etc). Makes sense?
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    Does anyone have the specimen paper to send to me?
    plspls x
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    One little question peeps..
    When we write a null hypothesis, we write something like "There is no significant ..... between ..... and ......"
    So, when we write a hypothesis do we write "There is a significant ...... between ...... and ......"
    or do we write "..... has an effect on ......"???
 
 
 
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