Biology Paper 61 ANSWERS ARE HERE!!!!!

[Ahmed GolD]

Q1) (a) The cells in water gained water by osmosis down their water potential gradient and became turgid leading to firm cells. The cells in salt solution lost water by osmosis down their water potential gradient and became flaccid leading to soft and slimy cells. The cells in dry air did not gain/lose water (no osmosis/no net movement) as there was no water potential gradient.

(b) Improvements:
Repeat to reduce errors, use an accurate stop-watch, wider concentration of salts in salt solution and use surface area of leaf rather than it's length.

 

[Ahmed GolD]

ASK ANYTHING I AM A BIOLOGY EXPERT. THIS IS NOT A JOKE!!!!

 

[Mahmoud khairy]

exam was easy ,, i think that ,, paper 3 will be hard ,,

 

[Ahmed GolD]

exam was easy ,, i think that ,, paper 3 will be hard ,,

If you can do June 2011 paper 3, it should be a piece of cake (IT IS FOR ME!!!)

 

[Mahmoud khairy]

june 2011 is easy ,, the hard was in p6,, in j11 ,, but the problem for me is the time ,, i solve all questions but i take about 1:30 hours ,, i tried many ,, but i'm still trying

 

[Micro961]

Should we label the white or black area for mesophyll cell?
And the concentration of sugar, we had to mention something to do with colour darkness?
And last question which was 1 mark, what was the answer?

 

[svenas]

ASK ANYTHING I AM A BIOLOGY EXPERT. THIS IS NOT A JOKE!!!!

last question I wrote as some of them are still growing is it correct??

 

[svenas]

Q1) (a) The cells in water gained water by osmosis down their water potential gradient and became turgid leading to firm cells. The cells in salt solution lost water by osmosis down their water potential gradient and became flaccid leading to soft and slimy cells. The cells in dry air did not gain/lose water (no osmosis/no net movement) as there was no water potential gradient.

(b) Improvements:
Repeat to reduce errors, use an accurate stop-watch, wider concentration of salts in salt solution and use surface area of leaf rather than it's length.

also for improving the results can I write :
1)make the length taller (>2)
2)keep experiment for a longer time??

 

[aliasal]

wat was the answer for the last part plz help!!

 

[Abu mota]

i dont think a stop watch is right as it was 10 minutes, stop watch is only used for short time intervals, also he was just comparing the difference between distilled water and salt solution so we dont need various range of salt solutions concentrations. in my opinion, the right answers are try to use mass instead of just touching them and feeling them and also repeat. ty

 

[svenas]

wat was the answer for the last part plz help!!

I wrote as some of them r still growing i.e age difference
But I'm worried dat it's variation?? wat u think?

 

[aliasal]

I wrote as some of them r still growing i.e age difference
But I'm worried dat it's variation?? wat u think?

i wrote the same thing but some of my friends wrote continuos variation i think both are right

 

[svenas]

i dont think a stop watch is right as it was 10 minutes, stop watch is only used for short time intervals, also he was just comparing the difference between distilled water and salt solution so we dont need various range of salt solutions concentrations. in my opinion, the right answers are try to use mass instead of just touching them and feeling them and also repeat. ty

I wrote increse lenght and I also wrote that time period should be increased...wat u thnk?

 

[Abu mota]

i wrote continuous variation for the last one

 

[svenas]

i wrote the same thing but some of my friends wrote continuos variation i think both are right

me too I thnk like that...try to ask a teacher ok?

 

[aliasal]

me too I thnk like that...try to ask a teacher ok?

for the labelling question did u label the empty space for the mesophyl layer or the walls?

 

[Abu mota]

i think that time period want really matter nor length srry because length and time affects both so if it was 5 minutes both will be affected the same and if it was 10 minutes both will be affected the same, and also length as long as they have the same length it doesnt affect the results.

 

[svenas]

i wrote continuous variation for the last one

I wrote age difference wat u thnk?

 

[svenas]

i think that time period want really matter nor length srry because length and time affects both so if it was 5 minutes both will be affected the same and if it was 10 minutes both will be affected the same, and also length as long as they have the same length it doesnt affect the results.

no but I thnk results will be more accurate ryt?

 

[aliasal]

i think that time period want really matter nor length srry because length and time affects both so if it was 5 minutes both will be affected the same and if it was 10 minutes both will be affected the same, and also length as long as they have the same length it doesnt affect the results.

i wrote repeat the experiment and take the average, use more than one leaf for each concentration, and something else i dont exactly remember