Biology/Physics ATP Preparation Thread

[RockStar15]

Guys discuss question relating to Physics ATP too...

 

[abcde]

I thought the same! But I didn't have the self-pollination prevention method in mind. Thanks for that! Every one, Please pray for me!

 

[Silent Hunter]

i have a question http://www.xtremepapers.me/CIE/Cambridg ... 2_qp_4.pdf

QUESTION 3

 

[workaholic]

Well its easy.a) Take the ruler to one side and set it into oscillation. Note the time taken (t) for 40 oscillations. Divide t by 40 to find the time taken for one oscillation.Repeat and average.
b) The fiducial marker acts as a marker so that the student knows when one oscillation gets completed. Its in the centre as the speed of the swing is maximum here.
c)Repeat and average. Increase the number of oscillations to give more reaction time

Correct me if Im wrong!!!

 

[intelnehalem]

Well its easy.a) Take the ruler to one side and set it into oscillation. Note the time taken (t) for 40 oscillations. Divide t by 40 to find the time taken for one oscillation.Repeat and average.
b) The fiducial marker acts as a marker so that the student knows when one oscillation gets completed. Its in the centre as the speed of the swing is maximum here.
c)Repeat and average. Increase the number of oscillations to give more reaction time

Correct me if Im wrong!!!

Absolutely correct mate! :beer:
Add to that, a fiducial marker if used to know when to start/stop the stopwatch.
oh and remember for all questions involving oscillations, the above is important(fiducial markers, repeating,doing it for more than 10 times etc)
All the best!

 

[Silent Hunter]

how to draw a diagram? in part (a)

 

[abcde]

Tips on testing for Reducing Sugar/lipids/Protein/Starch
Starch:
Crush and grind a given solid sample
either you can make a solution with this or you can directly proceed to adding Iodine solution
Place the sample on a WHITE TILE (important!!)
Add Iodine SOLUTION (iodine disqualifies, it should be iodine solution)
Colour change:
red brown to blue black if starch is present

You cannot make a solution with starch. I read that in a mark scheme some while ago. Just wanted to clear that.

 

[abcde]

The only tests which can be carried out on a solution of the test material in water are reducing sugar and protein!

 

[intelnehalem]

Tips on testing for Reducing Sugar/lipids/Protein/Starch
Starch:
Crush and grind a given solid sample
either you can make a solution with this or you can directly proceed to adding Iodine solution
Place the sample on a WHITE TILE (important!!)
Add Iodine SOLUTION (iodine disqualifies, it should be iodine solution)
Colour change:
red brown to blue black if starch is present

You cannot make a solution with starch. I read that in a mark scheme some while ago. Just wanted to clear that.

Actually you can ! We used starch solutions for actual practicals in our labs fyi

 

[izzahzainab]

whats the different between mitosis and miosis?
if miosis produces 4 daughter cells, then how come daughter cells have 23 chromosomes? they should have 46/4 chromosomes???? :x
when do we have a HAPLOID cell with 23 chromosomes?? :fool:

 

[abcde]

whats the different between mitosis and miosis?
if miosis produces 4 daughter cells, then how come daughter cells have 23 chromosomes? they should have 46/4 chromosomes???? :x
when do we have a HAPLOID cell with 23 chromosomes?? :fool:

First the chromosomes duplicate and then they produce four daughter cells. The detail isn't important though. All you need to know is the definition of meiosis which is " a form of nuclear division called reduction division such that the daughter nuclei produced contain half the number of chromosomes (haploid) as the parent nucleus (diploid).

 

[intelnehalem]

whats the different between mitosis and miosis?
if miosis produces 4 daughter cells, then how come daughter cells have 23 chromosomes? they should have 46/4 chromosomes???? :x
when do we have a HAPLOID cell with 23 chromosomes?? :fool:

In meiosis, a cell undergoes reduction division to form 2 haploid daughter cells which divide my mitosis to form a total of 4 haploid daughter cells.
Details of meiosis is not required for the OL syllabus.
Haploid cells are always 23 chromosomes for humans and they are gametes.
Diploid cells have 46 chromosomes in Humans!

 

[izzahzainab]

details not required, aah, sigh of relief. i almost banged my head worrrying over it

 

[dragoninja98]

lol ! done with physics
In oct i literally re drew and erased my graph 9 times....i was confused but Shukar hai Allah ka
Got an A* !
BUT am tensed about bio as i only took it up 3 months ago
any advice ?
I have done past papers of 2010,2006 to 1998
Are they enough ?
Please pm me !

 

[KarachiRocker]

@dragonninja, go thru the 2011 Biology Syllabus posted on CIE website / Xtremepapers. If you find nothing new in there and able to solve the past papers regarding those chapters, you are done with it and then you can chillo-fy (relax)

 

[abcde]

Can any one help me with question 2) (a) (iii) and (iv) of this bio atp: http://www.xtremepapers.me/CIE/Cambridg ... 6_qp_6.pdf

 

[intelnehalem]

Can any one help me with question 2) (a) (iii) and (iv) of this bio atp: http://www.xtremepapers.me/CIE/Cambridg ... 6_qp_6.pdf

 

[abcde]

You sure?

 

[intelnehalem]

You sure?

Yes ! We got the same question once at school and those were the answers

 

[uberleet]

Hey guyz,can you please guide me how I should prepare for ATP of bio and physics?Should I read the whole text book again or just go over the notes and focus on some important topics?And could you please tell me which topics I should focus on?

thnx