Physics, Chemistry and Biology: Post your doubts here!

[AAnsarii]

During breathing IN, external intercostal muscles contract, internal intercostal muscles relax, diaphragm contracts moving downwards, the rib cage moves up and out pulling the lungs and thus increasing their volume. And as in Physics, pressure is inversely proportional to volume so an increase in volume decreases pressure, this forces air INTO the lungs from high to low pressure to even out the pressure difference. During breathing out the reverse happens!
Hope this helps !

jazakillah, sis may Allah help us

 

[AAnsarii]

w02 ms1?

if sby's got it, PLEASE post it here

 

[thats_me]

if sby's got it, PLEASE post it here

 

[imperial]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Biology (0610)/0610_w11_qp_12.pdf
21 << explain this whole experiment about and how it work

 

[thats_me]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Biology (0610)/0610_w11_qp_12.pdf
21 << explain this whole experiment about and how it work

Here..
This experiment is for the uptake of oxygen ,There are two test tubes
The one joined with tube X has germinating seeds & the one joined with tube Y has dead seeds
Both have soda lime present that absorbs carbondioxide
Respiration takes place only through the tube X (as Y contains dead seeds)
The seeds need oxygen which they take from the coloured water (the carbondioxed released is absorbed by soda lime)
So, there is a rise in tube X and tube y is unchanged .. Ans is D

 

[AAnsarii]

View attachment 12549

jazakillahu khairaa

 

[imperial]

Here..
This experiment is for the uptake of oxygen ,There are two test tubes
The one joined with tube X has germinating seeds & the one joined with tube Y has dead seeds
Both have soda lime present that absorbs carbondioxide
Respiration takes place only through the tube X (as Y contains dead seeds)
The seeds need oxygen which they take from the coloured water (the carbondioxed released is absorbed by soda lime)
So, there is a rise in tube X and tube y is unchanged .. Ans is D

but what is this coloured water?? how do we know it raise or fall? what does make it rise or fall?

 

[Maz]

but what is this coloured water?? how do we know it raise or fall? what does make it rise or fall?

The germinating seeds use up the oxygen present in the tube, so the pressure acting upon the coloured water becomes less and therefore the air pressure acting on the water causes the water level to rise.
This does not occur in the other tube, since no oxygen is being used from the tube. (as mentioned by thats_me)

 

[imperial]

The germinating seeds use up the oxygen present in the tube, so the pressure acting upon the coloured water becomes less and therefore the air pressure acting on the water causes the water level to rise.
This does not occur in the other tube, since no oxygen is being used from the tube. (as mentioned by thats_me)

ty to you and thats_me, helped me too much

 

[Maz]

ty to you and thats_me, helped me too much

No prob.
You know, I ain't really used to these shortcuts like 'k' and 'btw', so it took me some time to make out what you meant by 'ty'. ( if i am not wrong, it's thank you right?)

 

[thats_me]

ty to you and thats_me, helped me too much

ur most welcum

No prob.
You know, I ain't really used to these shortcuts like 'k' and 'btw', so it took me some time to make out what you meant by 'ty'. ( if i am not wrong, it's thank you right?)

lol yes it is

 

[Rahma Abdelrahman]

Please help..
N 98 - Q20, ms says C, but I believe it's D as both rate and depth of breathing should increase!
N 2000 Q15, shouldn't be C (duodenum) not ileum(D) ?

Q24, ms says A, but shouldn't the plumule also show negative geotropism (C) ???​

Please someone help in these 3 questions !

 

[L.V.D]

sm stay in d food chain, they accumulate, increasing by evry step..
crops r saved when pests intending 2 eat them r killed, maybe dat should help
sorry im not of much aid

that was beneficial thanks

 

[L.V.D]

Please help..
N 98 - Q20, ms says C, but I believe it's D as both rate and depth of breathing should increase!
N 2000 Q15, shouldn't be C (duodenum) not ileum(D) ?

Q24, ms says A, but shouldn't the plumule also show negative geotropism (C) ???​

Please someone help in these 3 questions !

I heard you love chemistry how come?
coz i hate it so much
tell me more

 

[Rahma Abdelrahman]

Please help..
N 98 - Q20, ms says C, but I believe it's D as both rate and depth of breathing should increase!
N 2000 Q15, shouldn't be C (duodenum) not ileum(D) ?

Q24, ms says A, but shouldn't the plumule also show negative geotropism (C) ???​

Please someone help in these 3 questions !

PLEASE SOMEONE ANSWER ME....PLEASE!!

 

[thats_me]

Please help..
N 98 - Q20, ms says C, but I believe it's D as both rate and depth of breathing should increase!
N 2000 Q15, shouldn't be C (duodenum) not ileum(D) ?

Q24, ms says A, but shouldn't the plumule also show negative geotropism (C) ???​

Please someone help in these 3 questions !

for 20 the ans is D
q15 I think its duodenum and illeum absorbs the products of fat digestion
n 24 is also C :S
try checking the ms again :S

 

[Rahma Abdelrahman]

for 20 the ans is D
q15 I think its duodenum and illeum absorbs the products of fat digestion
n 24 is also C :S
try checking the ms again :S

Thanks , but are you sure abt 24!!

 

[thats_me]

Thanks , but are you sure abt 24!!

Yess!

 

[AAnsarii]

Difficult pprs, ppl...
?

 

[Rahma Abdelrahman]

Difficult pprs, ppl...
?

I believe it is impossible to find a difficult paper, but u will find a few difficult questions in each paper!