*Biology Paper 5 tips*

[boxfire1995]

Has there been any question to draw graphs and error bars? If yes then please be kind enough to post them. Thanks

There was just one, i dont remember the variant.
All you have to know is how to plot a graph and how to find the standard error. (It is standard deviation/underoot n)
That value you will have to plot above and below the point, you know like you do in physics. For instance, you get an error of 5. You that means your value will be +-5. I hope youre getting this.

 

[Lujain M.]

nov

Has there been any question to draw graphs and error bars? If yes then please be kind enough to post them. Thanks

november 10 variant 3 Q1part c (iii)

 

[xX1234Xx]

I have a few questions.

What would be a reason for anomalous value in an experiment?
Why is replicating data important?

 

[Dukeofwin]

There was just one, i dont remember the variant.
All you have to know is how to plot a graph and how to find the standard error. (It is standard deviation/underoot n)
That value you will have to plot above and below the point, you know like you do in physics. For instance, you get an error of 5. You that means your value will be +-5. I hope youre getting this.

Yups got it Thanks alot (Y)

 

[Dukeofwin]

nov

november 10 variant 3 Q1part c (iii)

Thanks a Big! Appreciate it

 

[moonangel996]

Please help me in question 3 how did they found the Expected value ?? and degree of freedom?? and the probability of the values is always 0.05 why this time its is 0.001 ??
PLEASE HELP ME
The question paper link
http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w07_qp_5.pdf
And the mark scheme
http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w07_ms_5.pdf

 

[maronamaro]

Im sorry for a late reply.
It depends on the values. You see, in a graph with continuous data, some values may have overlapping bars and some might not. But just know this.
If error bars overlap, no significant difference, if they dont, there is significant difference and null hypothesis will have to be rejected. --> its a rule.

THANKS MAN!!!!! SUPERB

 

[areebaization]

Please help me in question 3 how did they found the Expected value ?? and degree of freedom?? and the probability of the values is always 0.05 why this time its is 0.001 ??
PLEASE HELP ME
The question paper link
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_5.pdf
And the mark scheme
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_ms_5.pdf

There are 3 samples (grazed for 2 years ungrazed, for 10 years andungrazed for 30 years) so degree of freedom is n-1= 3-1 =2
secondly, I think they are accepting 0,05 probabilty. However, someone else might give a better answer.

 

[Alool]

guys plz help with o/n 2007 . Q3.. how do u calculate the expected?

 

[Dukeofwin]

Please help me in question 3 how did they found the Expected value ?? and degree of freedom?? and the probability of the values is always 0.05 why this time its is 0.001 ??
PLEASE HELP ME
The question paper link
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_5.pdf
And the mark scheme
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_ms_5.pdf

There are 3 samples (grazed for 2 years ungrazed, for 10 years andungrazed for 30 years) so degree of freedom is n-1= 3-1 =2
secondly, I think they are accepting 0,05 probabilty. However, someone else might give a better answer.

For b) ii) The explanation to answer is: Our Chi-Square value is 39.8 which is a much much larger value than the one given in row 2( i.e in the row of degree of freedom '2') of probability 0.05(since its a critical one). That means our value is way over the right side and thus the answer is 0.001(since it is on the extreme right and last of the probabilities).

AND for iii) Since our value is greater the difference is significant and is due to some other factor which you can go through from the marking scheme.

I hope I make some sense

 

[Muhammad TAimoor]

I have a few questions.

What would be a reason for anomalous value in an experiment?
Why is replicating data important?

Reason for anomalous value basically depends upon the question. If the question is about chromosomes, anomalous value might have occured due to a mutation or an abnormal division. Look for the question for clues

 

[Alool]

For b) ii) The explanation to answer is: Our Chi-Square value is 39.8 which is a much much larger value than the one given in row 2( i.e in the row of degree of freedom '2') of probability 0.05(since its a critical one). That means our value is way over the right side and thus the answer is 0.001(since it is on the extreme right and last of the probabilities).

AND for iii) Since our value is greater the difference is significant and is due to some other factor which you can go through from the marking scheme.

I hope I make some sense

how is the expected calculated?

 

[n00bfi]

Can someone please provide me with the text of the original post? Atm when I copy it and paste it the black background is also copied and I can't print that. Any help would be most welcome.

Thank you very much

 

[hush puppy]

hey! anybody done with their p5?

 

[Dukeofwin]

how is the expected calculated?

You calculate it by taking the mean of the observed!
In http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w07_qp_5.pdf Q3 you take out the mean of 36+90+114/3 and you get 80 but marking scheme says you can also use the highest value of 114

 

[Alool]

You calculate it by taking the mean of the observed!
In http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w07_qp_5.pdf Q3 you take out the mean of 36+90+114/3 and you get 80 but marking scheme says you can also use the highest value of 114

thanks a lot. i was breaking my head on this

 

[Oishee Asif]

If I am not wrong, Validity depends upon standard deviataion and T tests and Chi Test is concerned with reliability ? Aint it?

No, first dude was right.
Reliability is such that when you repeat the experiment, your results are reliable enough to get the same results next time. They're valid only from tests.
Does that make sense?

 

[sandwich147]

Can someone please provide me with the text of the original post? Atm when I copy it and paste it the black background is also copied and I can't print that. Any help would be most welcome.

Thank you very much

You just copy the whole text and paste it in WORD using unformatted text paste. If you don't know how, there's a paste button on top of the WORD menu, click on the little arrow below it, then click special paste and there should be 'unformatted text'.

 

[sitooon]

NO ONE SHOULD DISCUSS THE PAPER BEFORE 24 HR.
OTHERWISE ALL YOUR HARD WORKS WILL BE LOST AND GT WILL GO HIGH !
NOT EVEN SAYING WHAT THE EXAM WAS ABOUT .

 

[moonangel996]

There are 3 samples (grazed for 2 years ungrazed, for 10 years andungrazed for 30 years) so degree of freedom is n-1= 3-1 =2
secondly, I think they are accepting 0,05 probabilty. However, someone else might give a better answer.

Thank you