Biology P33 8 Nov

[niya15]

The concentrations u made wud have been there if they had asked us to half the already made concentrations. This was not a serial dilution.

sorry i ws talking abt concentration..... i made 0.4 ,0.2,0.1,0.05 ...how many marks i ll loose?

 

[xtremeforums]

I made these concentrations since they wanted a difference of 0.1% between each successful conc. Will these be accepted because I feel they may be wrong?

0.4%, 0.32%, 0.26, 0.16 & 0.06

I dont think so, because the difference in concentration is not 0.1%

 

[Idolfanatic95]

yup thats what i did.
And the estimation of concentration in the sample was 0.3%?

Me n my frnd wrote 0.5% cuz it took the least time for a color change to appear :O

 

[TCHS]

I dont think so, because the difference in concentration is not 0.1%

the differences are 0.12% which when rounded is 0.1%. Then the next difference is 0.06% which when rounded is also 0.1%. Then finally the difference is 0.1%.

Will they still cut marks?

 

[Idolfanatic95]

sorry i ws talking abt concentration..... i made 0.4 ,0.2,0.1,0.05 ...how many marks i ll loose?

Well im not sure but yeah more than 5 atleast since there were 2 tables where u had to put in these concentrations and for the last ques u were talking abt, the part whr u drew diagrams instead of writing down differences, u'll lose 2 or 3

 

[niya15]

Well im not sure but yeah more than 5 atleast since there were 2 tables where u had to put in these concentrations and for the last ques u were talking abt, the part whr u drew diagrams instead of writing down differences, u'll lose 2 or 3

how many tables u made n wht were exact headings ??

 

[xtremeforums]

For the calibration question... what did u get?

 

[TCHS]

Me n my frnd wrote 0.5% cuz it took the least time for a color change to appear :O

Oh, I asked my teacher about it & she said that the examiners fooled us in that question. She said they were told to prepare the seeds in such a way that the outer coating was of glucose, therefore the actual answer was 0.4% which is the initial concentration. She said perhaps they'll accept answers close to 0.4%

 

[Idolfanatic95]

Oh, I asked my teacher about it & she said that the examiners fooled us in that question. She said they were told to prepare the seeds in such a way that the outer coating was of glucose, therefore the actual answer was 0.4% which is the initial concentration. She said perhaps they'll accept answers close to 0.4%

so 0.3 or 0.5% wud be accepted? Well i hope so

 

[xtremeforums]

how many tables u made n wht were exact headings ??

We had to make 2 tables...
First one: Test tube number, Volume of distilled water, Volume of 0.4% reducing sugar, Concentration made. With units ofcourse.
Second one: Concentration of sample, time taken for initial colour change, color change, Conclusions

 

[TCHS]

so 0.3 or 0.5% wud be accepted? Well i hope so

Yeah that's what she said. I hope so too!

 

[xtremeforums]

Oh, I asked my teacher about it & she said that the examiners fooled us in that question. She said they were told to prepare the seeds in such a way that the outer coating was of glucose, therefore the actual answer was 0.4% which is the initial concentration. She said perhaps they'll accept answers close to 0.4%

i got 0.3%, so did my teacher...

 

[xtremeforums]

Yeah that's what she said. I hope so too!

how are people getting 0.5%? :S
U were suppose to compare with the solutions u made.. and 0.4 was the most concentrated. U cant guess and write 0.5%...

 

[Idolfanatic95]

The differences in the last part between slide K1 and figure 2.4. What did u all write?

 

[TCHS]

i got 0.3%, so did my teacher...

I got 0.32% too but she said they had told her to prepare it in that way but hopefully they will accept answers such as 0.3%

 

[xtremeforums]

I got 0.32% too but she said they had told her to prepare it in that way but hopefully they will accept answers such as 0.3%

yah, hopefully

 

[niya15]

We had to make 2 tables...
First one: Test tube number, Volume of distilled water, Volume of 0.4% reducing sugar, Concentration made. With units ofcourse.
Second one: Concentration of sample, time taken for initial colour change, color change, Conclusions

i also made two tables ...in 1st one i wrpte vol of R , volume os water n percentage and in second %age of R ,observation,time taken an amount of sugar....

 

[TCHS]

The differences in the last part between slide K1 and figure 2.4. What did u all write?

what did you write?? I was a bit confused :s

 

[Irfan1995]

1) Concentrations are supposed to be reduced by 0.1%, so if anything is rounded to that, I don't think it's fair to deduct more than 1 mark. Also, last time I checked, ecf was applicable, do there's no way you could lose too many marks
2) It's literally impossible for every single students to get identical seeds. So we're definitely going to get different very different answers estimating the concentration of reducing sugars. Mine, for example, was around 0.44%, other students in my class got between 0.2% to 0.5%. I think anything within that range is acceptable.

 

[Idolfanatic95]

what did you write?? I was a bit confused :s

I wrote about the vascular bundles like in K1 they were in the centre and the xylem was start shaped. I wrote about the absence of pith and cambium in K1. and then the thickness of cortex. and also that there were more vascular bundles present in fig 2.4 than K1