*Biology Paper 5 tips*

[biba]

guys!!! now chillax! i think u should stop doing papers now! get some sleep if u havnt!!!!
by the GRACE and MERCYof ALLAH and with so much help from knowitall10 and Irfan1995, we wil all ace our examz IN SHA ALLAH!!!

 

[knowitall10]

Good Luck everyone!! We will ace tomorrow's test no matter what it takes..and guys: I'll Miss you all soooooooooooo much inshAllah ='(

and biba , you were the awesome-est person out there..if it weren't for your motivation, I would never have come to this state...and for that,

I salute you...​

​

​

 

[biba]

Good Luck everyone!! We will ace tomorrow's test no matter what it takes..and guys: I'll Miss you all soooooooooooo much inshAllah ='(

and biba , you were the awesome-est person out there..if it weren't for your motivation, I would never have come to this state...and for that,

I salute you...​

​

​

jazakALLAH !!
but i hav been good-for-nothing participant in this thread cuz i was too lazy to do bio p5 and put all my time in phy p5
i will miss u toooooo! genius!

 

[knowitall10]

jazakALLAH !!
but i hav been good-for-nothing participant in this thread cuz i was too lazy to do bio p5 and put all my time in phy p5
i will miss u toooooo! genius!

You played a huge role in motivating me biba and I am not leaving XPC inshAllah

 

[kelly sheers]

Actually, most scientific calculators have a cute little "standard deviation" button. It has the small Greek "sigma" sign.

yup but they dont directly ask for the answer always nah. sometimes you gota do the steps right?

 

[faangelica]

yup but they dont directly ask for the answer always nah. sometimes you gota do the steps right?

plzzz answer my question oct nov 2009 question 2 part b paper 51

 

[knowitall10]

plzzz answer my question oct nov 2009 question 2 part b paper 51

Add the sample to the slide, unifromly distribute it.
Count the number of cells lying in the 0.2mm x 0.2mm part of the grid. The cells which are more than half outside the grid will not be counted, otherwise, they're counted as one cell.
This number is then multiplied with 250 (the vol of the cells) and the whole thing divided by the volume of the grid : 0.2 x 0.2 x 0.1 = 0.04mm^3
Count minimum of 3 areas for reliability and accuracy..
Hope I helped you
All the best inshAlla! We'll be amazing

Good Night Everyone!! Assalamu 'Alaykum wa Ra7matullahi wa Barakatuhu!!!!!!

 

[knowitall10]

faangelica quick!! I posted the answer up there!!

 

[Duamask]

Good luck to everyone! inshaAllah it will be great by the grace of god. Relax, Sleep well, eat well, and think well. Leave the rest to Allah s.w.t and perform your best.
InshaAllah!

 

[Just visiting]

Alert!
For all ya guys out there freaking about error bars and standard error , imma make it clear once and for all ISA.
You need to knoww that there is a difference between standard deviation and standard error.
standard error is (standard deviation)/(root of no. of sample {root n})
when plotting bars, you need +/- standard deviation
so you need to multiply the standard error with (root n)
this value will be +/- the bar

P.S. the value of n will be the value that is going to be subtracted to find degrees of freedom

 

[marz_katy]

Alert!
For all ya guys out there freaking about error bars and standard error , imma make it clear once and for all ISA.
You need to knoww that there is a difference between standard deviation and standard error.
standard error is (standard deviation)/(root of no. of sample {root n})
when plotting bars, you need +/- standard deviation
so you need to multiply the standard error with (root n)
this value will be +/- the bar

P.S. the value of n will be the value that is going to be subtracted to find degrees of freedom

tnx aloot=)

 

[Soldier313]

Thanx! I was just thinking why the formula was diff from the one used in stats
anyways sorry but er what exactly is the diff btwn sample and population standard devs?
Thank you so much!

EDIT: Look at the next part of the qn, the graph plotting bit, the ms says the means are 55.9 and 122. However, the means i calculated were 56.0 and 123.3!!

Irfan1995 ? need some help please
knowitall10 geek101 Or if you guys could please clarify this doubt?

Just visiting could you please look at my doubt?

 

[marz_katy]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_w09_qp_52.pdf
can any1 plz xplain me 2(b) plzzzzzzzzzzzzz

 

[Just visiting]

http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w09_qp_52.pdf

can any1 plz xplain me 2(b) plzzzzzzzzzzzzz

Hey
Just try to understand ok?
that 1/.25 x 6 just keep it as 6/0.25 for better understanding
1st he found the area of slide then multiply by pollen entering per mm
so (10*42)*6/0.25
6/0.25 is pollen grains enterring per mm
then this is for every 10 dm^3 of air per min
we need for 6 hrs
1m^3 is 1000 dm^3
so to make that 10 dm/min to m/min we divide by 1000
then for hrs instead of min we multiply by 60
then for 6 hrs we multiply by 6
now we have (10*60*6/1000)
read working + ms for better understanding

 

[marz_katy]

Hey
Just try to understand ok?
that 1/.25 x 6 just keep it as 6/0.25 for better understanding
1st he found the area of slide then multiply by pollen entering per mm
so (10*42)*6/0.25
6/0.25 is pollen grains enterring per mm
then this is for every 10 dm^3 of air per min
we need for 6 hrs
1m^3 is 1000 dm^3
so to make that 10 dm/min to m/min we divide by 1000
then for hrs instead of min we multiply by 60
then for 6 hrs we multiply by 6
now we have (10*60*6/1000)
read working + ms for better understanding

got it=) tnxxxx....can u xplain me how to gain full marks in the support and not support ques...i mean do dey gv marks fr qouting datas?

 

[geek101]

knowitall10 YAR, LAST EXAM?? GOOD LUCK TO YOU TOO!!

 

[faangelica]

hey i've got my exam over with ,havnt u guys given your exam

 

[faangelica]

t

Add the sample to the slide, unifromly distribute it.
Count the number of cells lying in the 0.2mm x 0.2mm part of the grid. The cells which are more than half outside the grid will not be counted, otherwise, they're counted as one cell.
This number is then multiplied with 250 (the vol of the cells) and the whole thing divided by the volume of the grid : 0.2 x 0.2 x 0.1 = 0.04mm^3
Count minimum of 3 areas for reliability and accuracy..
Hope I helped you
All the best inshAlla! We'll be amazing

Good Night Everyone!! Assalamu 'Alaykum wa Ra7matullahi wa Barakatuhu!!!!!!

thx ,this question came in exam,but unfortunatly i logged off before you replyed ,so didnt read yor answer .but anyways thx alot,you r gr8

 

[Irfan1995]

Irfan1995 I need a clarification in the examiner's report this time. In the sources I have read so far, and in the comment which you and many others gave regarding the standard error and the bars, I understood that we multiply by 2. Now I ask, as another person already did in this post, why did they say in the examiner's report of w10 p53 1c)(iii) (and mark scheme as well), only +/- the standard error about the bar graph, not 2x standard error?

According to the mark scheme, both answers are correct. That is, it would be correct if you take the error bars +/- 2x standard deviation. It's also correct to take the error bars +/- standard error.

 

[Irfan1995]

Everyone seems to be confused between the error bars based on the standard deviation, and those based on the standard error.

Error bars whose range is +/- 2x standard deviation:
This shows that 95% of the data in one set can be found within two standard deviations from the mean.

Error bars whose range is +/- standard error:
If you calculated the mean weight in a class to be 70 kg (it's just an example), and the standard error is 2 kg, you are 95% sure that the mean of another class is between 68 kg and 72 kg (2 kg away from the original mean). This is when you're estimating the mean of another set based on a calculated mean.