*Biology Paper 5 tips*

[Marks&Spencers]

Ok what i've gathered so far from doing past papers is that:
----> when error bars overlap, there is no significant factor causing a difference in the values (diff due to chance)
-----> when error bars don't overlap, there is a sugnificant difference in values meaning an external or factor other than chance is playing a hand in making the values so different!

Say for example we're investigating the effect of temp on bacteria. (im making this up for explanation purposes)
If error bars for the % of surviving bacteria for temperatures 10 20 30 40 and 50 overlap, this means that at these temperatures, the temperatures have no different effects on the bacteria so we would conclude that NO DIFFERENCE BETEWEEN VALUES. This shows that temperature has no effect.

And you cam hopefully conclude the opposite if error bars didn't overlap.
That the tmperature was having some effect on bacterial survival!

Anyone correct me if i'm mistaken but thats my take on it!
Hope i helped!

Did help a lot! Thank you so much! And do you know how we calculate the bars themselves, like the whole thing with the standard error and everything?

 

[MaxStudentALevel]

Did help a lot! Thank you so much! And do you know how we calculate the bars themselves, like the whole thing with the standard error and everything?

I'm glad! Could you take a look at my question on the previous page?

And the error bar is the standard error! (SM) which is calated by s/(square root of n)
-----> Example 50 (+-) 20
The error bar would be 20 above 50 and 20 below 50
So total error would be 40 (up amd down)
It shows the possible deviation of the value!

 

[Just visiting]

hey guys ,
I need your help in p5. So , i want the syllabus for p5 , i know there isn't but i just want to know what topics are there.
also i need to know precautions, not like those in post #1 i mean like when heat is there or when cutting (those that are usually safe)
So thanks in advance

 

[Just visiting]

also if anyone knows about t, z, and chi square tests plz tell me

 

[knowitall10]

hey guys ,
I need your help in p5. So , i want the syllabus for p5 , i know there isn't but i just want to know what topics are there.
also i need to know precautions, not like those in post #1 i mean like when heat is there or when cutting (those that are usually safe)
So thanks in advance

Assalamu 'Alaykum
for heat: use heat-resistant gloves, or a heat-resistant mat t place the apparatus. never heat a test tube directly, always place in a water bath.
when cutting, there're aren't any safety precautions to consider as far as i know..so can u please tell me which question specifically asks such a thing? I'm sure we'll be able to help you InshAllah..

 

[Just visiting]

Assalamu 'Alaykum
for heat: use heat-resistant gloves, or a heat-resistant mat t place the apparatus. never heat a test tube directly, always place in a water bath.
when cutting, there're aren't any safety precautions to consider as far as i know..so can u please tell me which question specifically asks such a thing? I'm sure we'll be able to help you InshAllah..

There you go Click here to go to link (as i am a professional who can make hyperlinks, LOL )
BTW its Q1

 

[Just visiting]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_ps_13.pdf

Thanks Alice that was really helpfull

 

[knowitall10]

There you go Click here to go to link (as i am a professional who can make hyperlinks, LOL )
BTW its Q1

Good!
but where does it require safety?

 

[seneria]

when do we make use of stage micrometre and eye piece graticule...? like on what cases we must use....

 

[Just visiting]

Good!
but where does it require safety?

there is such a point in Marking scheme
and btw what are error bar? Thanls in advance

 

[Just visiting]

when do we make use of stage micrometre and eye piece graticule...? like on what cases we must use....

when you are making measurements under microscope

 

[Noor Ahmad]

question 3 b (iv) how do we find the number of degrees of freedom?

http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_s09_qp_5.pdf

 

[sandrawrr]

Could someone please explain to me what it means by "state the null hypothesis"

 

[magnesium]

when do we make use of stage micrometre and eye piece graticule...? like on what cases we must use....

to find actual lenght of the specimen under field of view ....by superimposing stage micrometre and eyepiece

 

[magnesium]

Could someone please explain to me what it means by "state the null hypothesis"

it means that there is no significant difference b/w 2 sets of data (might b more) being tested

 

[Student12]

I saw somewhere that someone had posted some links which were useful for Paper 5 ?
Or if anyone knws good links for p5?

 

[MaxStudentALevel]

Hey can anyone help with ON2007 Q3 (ii) part?
How do you find the expected values? I mean I get that it's all 3 added and divided by three but why?
And whats the general rule for expected values?
Marks&Spencers knowitall10 or anyone?

 

[Alice123]

knowitall10
AoA
hope your SAT went as awesome as u are
I need help in bio
I still dnt get what "overlapping of error bars" is...
Will be really grateful if u explained it with some examples...
Thanks
PS: Dont get scared of my avy.... Got it as a dare

 

[dornam]

Here for AS, page 20: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_ps_1.pdf

Here for A2, second page: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_ps_13.pdf

And also here, at the chapters from L to U: http://www.cie.org.uk/docs/dynamic/43800.pdf

Here they are Student12

 

[dornam]

What solution can be used as a buffer?