Biology ATP

[mjeg18]

Since I cant revise all the past papers which years should i do, as in from 2010 to ___________ ? :unknown:

 

[Soulgamer]

Here are some of the Important ones I think:
1.May/June 2006 http://www.xtremepapers.me/CIE/Cambridg ... 6_qp_6.pdf
2.May/June 2010 http://www.xtremepapers.me/CIE/Cambridg ... 6_qp_6.pdf
3.Oct/Nov 2010 http://www.xtremepapers.me/CIE/Cambridg ... _qp_62.pdf
4.May/June 2003 http://www.xtremepapers.me/CIE/Cambridg ... 3_qp_6.pdf
5.May/June 2009 http://www.xtremepapers.me/CIE/Cambridg ... 9_qp_6.pdf
6.May/June 2007 http://www.xtremepapers.me/CIE/Cambridg ... 7_qp_6.pdf

and if you can some from 05,08.

 

[mjeg18]

I read this qs in some past paper " Why do we need dry test tubes for ethanol emulsion test ? " can someone elaborate on this?

 

[Soulgamer]

Fats are insoluble in water hence it first needs to be dissolved in ethanol thus when decanted in water a cloudy emulsion is formed.

 

[intelnehalem]

I read this qs in some past paper " Why do we need dry test tubes for ethanol emulsion test ? " can someone elaborate on this?

If the test tubes aren't dry, this will lead to an erroneous result ! The experiment will not be accurate

 

[adnanj]

@intel can u plz solve any magnification question and post up here..it comes every year and ms is not clear enough... thanks in advance

 

[intelnehalem]

@intel can u plz solve any magnification question and post up here..it comes every year and ms is not clear enough... thanks in advance

Sure but it is quite difficult to do it since we have to measure our own drawings! I'll try and do something !

 

[adnanj]

@intel can u plz solve any magnification question and post up here..it comes every year and ms is not clear enough... thanks in advance

Sure but it is quite difficult to do it since we have to measure our own drawings! I'll try and do something !

Thanks a lot.. but i never get how to do it... so if u could suggest any way?? i am not getting it at all... would be really helpful if u put up a solved question here.. i mightbe able to understand and do correctly in the paper becoz magnification comes for sure...

 

[intelnehalem]

The image what they given is a RBC and it's size is 1.8 cm (assumed ) I have drawn how to measure the size of the RBC there
In our drawing (mine sucks i drew it in a hurry for only this purpose) we have to find the size in the same way as the original !
So:
Maginification = Measured length(our drawing) / Actual length (of the drawing they give)
= 3.6/1.8 = x2
however , a RBC cannot be 1.8 cm Let's assume that they told us that the image of the RBC has been magnified by x250.
Then they will ask , find the magnification of YOUR drawing when compared with the actual sample (the very small RBC in our body)
therefore you have to calculate this way:
Magnification we found for our drawing when compared to the drawing in paper x the magnification of the drawing in paper when compared to the actual sample (RBC)
therefore :
2 x250 = x500
Our drawing of the RBC is 500 times magnified when compared to an actual RBC
Hope you understood!

 

[adnanj]

all magnification questions have to be followed this way????

 

[intelnehalem]

all magnification questions have to be followed this way????

Almost all ! Think carefully about whether they are asking for the magnification compared to the actual sample or for the magnification compared to the image on the question paper !
Good luck!

 

[adnanj]

thanks a lot.. and good luck to u too.. especially for ur english literature paper tomorrow...

 

[intelnehalem]

thanks a lot.. and good luck to u too.. especially for ur english literature paper tomorrow...

Thanks mate ! I'll need it for tmrw definitely
All the very best !

 

[Silent Hunter]

hey people how to prepare biology in these two days? should we go through the whole book or just the experiments in the book? and then past papers

 

[mjeg18]

What happens when we place a plant in :

(i) acidic soil
(ii) alkaline soil

explain ur answer with reference to wiltin, dying , osmosis, etc.

 

[mjeg18]

hey people how to prepare biology in these two days? should we go through the whole book or just the experiments in the book? and then past papers

It depends, try to look at as many diagrams, food tests, plant tests, etc as possible. If ur studying frm a book like federal then look at the summary at the end of each chapter and do revise , reproduction in plant and animals and inheritence. try to do past papers from 2003-4 to 2010, focusing on may / june papers more (not necessarily). Focus on graphs and practise drawing qs.Don't forget to revise potometer

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[izzahzainab]

What happens when we place a plant in :

(i) acidic soil
(ii) alkaline soil

explain ur answer with reference to wiltin, dying , osmosis, etc.

in short, if the soil is too concentrated, whether alkaline or acidic, the plant wilts.
acidic soil is especially unsuitable as acid in soil leeches away the nitrate and mineral ions. plant will eventually die.

most of the plants are well suited to alkaline soil. Im not sure why, but i guess it lets the nutrients stay as they are. in most of the countries, lime is spread on soil just to cancel out its acidity and to make it slightly alkaline