Biology; Chemistry; Physics: Post your doubts here!

[Muzammil ahmad]

No they aren't important, nor is there any question regarding them in the past papers...u just need to know the differences bw mitosis and meiosis which includes the pairing of homologous chromosomes etc.

No, I remember a question did come.
It was of 7 marks

 

[whyareallnamestaken]

Wait, Isint only water moved by transpiration

Yes, transpiration pull only moves water up the plant but that water has dissolved mineral salts in it, which are carried up the xylem.

 

[whyareallnamestaken]

No, I remember a question did come.
It was of 7 marks

Care to mention which year this question is from?

 

[whyareallnamestaken]

I actually wanted to ask about the ATP paper Of biology, I'm having my paper after 2 days and yet I'm not prepared for my exam. Would please help me out to find a convenient way to prepare my exam in a better and easy way and as well as in short time too. thanks.

http://znotes.org/ig-biology/

I think this covers most of everything you are likely to be questioned on. Solve a couple of past papers after reading through these notes, and you'll be good to go.

 

[fahadhameedahmad]

I am making video lectures www.fahadsacademy.com

if you have doubts related to chem, physics and math then contact me and i will post a youtube video lecture, find me on youtube by searching Fahad's Academy

 

[A*****]

Yes, transpiration pull only moves water up the plant but that water has dissolved mineral salts in it, which are carried up the xylem.

I said the same

 

[Anon_Assassin]

Salaam ppl
Can someone help me?
I need a labelled diagram of a storage granule?
ASAP tomo is Bio Olev

 

[Ayesha Asif333]

I actually wanted to ask about the ATP paper Of biology, I'm having my paper after 2 days and yet I'm not prepared for my exam. Would please help me out to find a convenient way to prepare my exam in a better and easy way and as well as in short time too. thanks.

I thought I was the only one

 

[whyareallnamestaken]

Salaam ppl
Can someone help me?
I need a labelled diagram of a storage granule?
ASAP tomo is Bio Olev

Are you talking about the storage granules in bacteria? As far as I know, those aren't a part of our syllabus.

 

[Asim Shah]

Salam . anybody have Philip Allan Magazines for CHEMISTRY

 

[Mikail Khan]

Hello!! I have a stupid question and i need guidance :V
is calculator allowed in GCE Chemistry/Physics P1,P2, and in ATP ?
& Which type of calculator is allowed and which is not?

 

[sweetiepie94]

https://www.xtremepapers.com/community/threads/o-level-notes-center.11138/
https://www.xtremepapers.com/community/threads/useful-stuff-compiled-for-o-level.6190/


hope this helps

 

[RAMEEZA]

Hello!! I have a stupid question and i need guidance :V
is calculator allowed in GCE Chemistry/Physics P1,P2, and in ATP ?
& Which type of calculator is allowed and which is not?

Yes
scientific calculators are allowed

 

[Mikail Khan]

Yes
scientific calculators are allowed

ok thanks!!

 

[Sofia James]

Hi! So i have a question. Firstly is the voltage at the negative terminal of the battery 0? if so why? and i know it is there to create a potential difference so that current can flow but is there any logical explanation. Also, whatevr comes in the exam it's mentioned in our CIE syllabus right? like nothing comes which is not included in the keypoints of our syllabus?

 

[Saadarsalan]

Regarding redspot's keypoints, calssified, topical, yearly solved. I cant say anything. I suggest to leave them and rather refer to your teachers since those keypoints are incomplete and often answers are incorrect.

 

[Sofia James]

Regarding redspot's keypoints, calssified, topical, yearly solved. I cant say anything. I suggest to leave them and rather refer to your teachers since those keypoints are incomplete and often answers are incorrect.

im talking about the keypoints in the syllabus (official CIE syllabus or 'learning outcomes' as you would call it

 

[Aajinkya]

A small cylinder of compressed helium gas is used to inflate balloons for a celebration.

(b) The helium in the cylinder has a volume of 6.0 × 10–3 m3 (0.0060 m3) and is at a pressure of 2.75 × 106 Pa.

(i) The pressure of helium in each balloon is 1.1 × 105 Pa. The volume of helium in an inflated balloon is 3.0 × 10–3 (0.0030 m3). The temperature of the helium does not change.

Calculate the number of balloons that were inflated.

I know how the calculation is done for this question using p1v1=p2v2 but my question is how can you equate the pressure and the volume of both systems if the mass of helium in both system is not equal?

_____________________________________________________________________________________________________________________

The gas in the cylinder cannot be emptied to create vacuum. So, once the pressure inside the cylinder equals atmospheric pressure, it stops pushing gas to the balloon. Hence the last balloon may not be inflated to full. Considering this, the available pressure in the cylinder initially has to be initial cylinder pressure - atmospheric pressure which is 2.75 × 10^6 - 1.01 × 10^5 = 2.64 x 10^6 Pa.

therefore, (2.64 x 10^6) * (6 x 10^-3) = 1.1 x 10^5 x v2

v2= 0.144 m^3

therefore, v2/ volume of helium in 1 balloon

= 0.144/0.003 =48

(remember there are many ways of doing a sum)

 

[mustafa4000]

Biology notes by sir Zafar Sulehri
https://m.mediafire.com/view/vx6ldiob91qoli8
Physics notes
https://m.mediafire.com/view/oed2g44bciahzf1

 

[Determinant86]

How do you guys get yourselves to study Biology?

The other two sciences have a mathematical portion so it's easier, for me at least, to push myself to practice them.