Biology P33 8 Nov

[InnocentAngel]

Anyone having a list of all the errors and improvements which are usually asked for ?
Im in short of time to analyse all the ms .
Please anyone having such a list , do share it here
Thanks in advance

 

[Ali Balouch]

SOURCES OF ERRORS!
1.temp nt controlled
2.pH not controlled or nt measured accurately
3.difficulty in judging the colour.
4.difficulty in having the same time
5.inaccuracy in preparing serial dilution
6.inaccuracy of equipment, fr e.g. pipette/syringe
7.too short time.
8.evaporation of the solution which can cause the concentration to change.

LIMITATIONS OF ERRORS!
1.measure the volume accurately using syringe with narrow range of calibration
2.repeat more times at each pH/conc./temp
3.use range of pH/conc./temp
4.accurate specific measuring devices
5.use colorimeter to measure the degree of colourness.
6.use buffer to control pHs
7.use of water bath/thermostat to control temp
8.use thermometer to measure the temp.
9.thermostatically controlled environment.
10.repeat with each conc.
11.volume of the sample(e.g. enzyme/substrate) must be the same..cuz as volume increases, conc also increases
12.keep only one factor different, and all others must be the same.

Reliability.....take minimum of 3 readings!
repeat with mre pH/conc/temp
and find out their mean
Accuracy.....seing electronic thermostat
use of pippettes instead of measuring cylinders

 

[niya15]

hey anyone having pictures of plan diagrams ??need thm urgently plzzz anyone thr help me ....

 

[waleed82]

GUYZ biology paper was xtremely owesum !!!!! was just a piece of cake for me!

 

[Twinks05]

does anyone have any idea of what might come in p33?
Will the content be similar to the may/june paper?

 

[niya15]

GUYZ biology paper was xtremely owesum !!!!! was just a piece of cake for me!

r u talking abt P33 biology??

 

[waleed82]

yea!

 

[niya15]

yea!

man biology practical paper 33 is tomorrow .....

 

[waleed82]

man biology practical paper 33 is tomorrow .....

hey LOOOOOOOOOOOOOL IGCSE biology Practical paper has already finished!

just MCQz are left n they r on comin 19!

well practical paper code is 62 NOT 33!

 

[niya15]

hey LOOOOOOOOOOOOOL IGCSE biology Practical paper has already finished!

just MCQz are left n they r on comin 19!

well practical paper code is 62 NOT 33!

oki...but this thread is for P33 ...i wz shocked to c ur comment

 

[waleed82]

oki...but this thread is for P33 ...i wz shocked to c ur comment

Well r u talkin about IGCSE?

 

[Nishii]

does anyone have any idea of what might come in p33?
Will the content be similar to the may/june paper?

am expecting "food test" practical, benedict's solution etc! and you?

 

[nelly trich]

Guys I am confused about whether to add unknowns results in the table or not ???

 

[nelly trich]

I need help Please my exam is tommorow

 

[Ali Balouch]

am expecting "food test" practical, benedict's solution etc! and you?

yahi ajaye Allah karay

 

[Ali Balouch]

I need help Please my exam is tommorow

unknown like?

 

[nelly trich]

In may 2011 varient 2 w hen you were required to estimate the glucose concentration of s1 and s2 which were the unknowns , the question stated that i had to do serial dillution to glucose concentration of 4 percent and record the time taken to observe the 1st color change of benedict solution

 

[nelly trich]

what do you think ?

 

[Twinks05]

Oh, I wasn't sure, in may/june we had to do an enzyme experiment with hydrogen peroxide, and also draw plan diagram of arteries and veins. Hope it's easier this time though =/
O/N papers are usually harder than M/J right? Do you know if the board will check winter session paper more strictly than m/j? is there any pattern?

am expecting "food test" practical, benedict's solution etc! and you?

 

[athaan]

Well r u talkin about IGCSE?

no, we're talking about A Level. I guess you're in the wrong subforum. xD

hmm, when was the last time there's a food test practical?