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Reply 2980
Original post by Linked
If you remove leaves - I understand that fewer stomata and smaller surface area reduce transpiration rate - but how is there a less cohesion/tension force?


Cohesion and Tension is formed by water evaporating.

Evaporation forms a suction which pulls more water into the leaf (cohesion). Water molecules are cohesive (they stick together) so when some are pulled into the leaf others follow. This means the whole column of water in the xylem from the leaves down to the roots moves upwards. Water then enters the stem via roots.
Resitting this exam tomorrow, got 128 first time round, really really hoping for 140/140 to guarantee an A overall this year.
Reply 2982
Original post by jemo9
Can somebody please just go over what we need to know about cancer for the exam? D:


Cancer is just a tumor that invades surrounding tissue.

Treatments for cancer have to be staggered to give the body a chance to recover and replace body cells. If too much chemotherapy is undergone the patient will die as a result of such body cell damage.
Good luck to you guys tomorrow, I'll keep you guys in my thoughts when revising for my Unit 2 Chemistry exam (edexcel) haha.

Is this a PM or morning exam for you lot?
Reply 2984
Once again what are the possible plant 6 mark question questions?


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Guys why do we use partial pressure of oxygen instead of using concentration of oxygen?
HELP PLEASE
Original post by James A
Good luck to you guys tomorrow, I'll keep you guys in my thoughts when revising for my Unit 2 Chemistry exam (edexcel) haha.

Is this a PM or morning exam for you lot?


Morning for me

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Reply 2987
Original post by James A
Good luck to you guys tomorrow, I'll keep you guys in my thoughts when revising for my Unit 2 Chemistry exam (edexcel) haha.

Is this a PM or morning exam for you lot?


AM :frown:
Reply 2988
Original post by LiamDaly
Once again what are the possible plant 6 mark question questions?


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I want to sleeeeeeeweeep


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Reply 2989
guys, can anyone tell me how many units of DNA are in each stage of the cell cycle, please? :colondollar:
Reply 2990
Original post by EmilyC96
Guys why do we use partial pressure of oxygen instead of using concentration of oxygen?
HELP PLEASE
Partial pressure is the amount of a gas that is present in a mixture of gases that is measured by the pressure it contributes to the total pressure of the gas mixture. I'm guessing we use partial pressure because it takes into account all of the other gases rather than just oxygen? :s-smilie:
Original post by EmilyC96
Guys why do we use partial pressure of oxygen instead of using concentration of oxygen?
HELP PLEASE



Partial pressure is basically the concentration of a gas in a mixture. Whenever we talk about haemoglobin, partial pressure is used because the affinity of haemoglobin is not affected by concentration of oxygen alone. It is also affected by other gases in air such as carbon dioxide, so partial pressure allows us to see the relative concentrations of the gases in air.
Original post by EmilyC96
Guys why do we use partial pressure of oxygen instead of using concentration of oxygen?
HELP PLEASE


Because it takes into account other gases in the air. The air you breathe in, as you know, is only 21 % oxygen. So you need to take into account the pressure of oxygen. It's like a universal thing to do with the air you breathe.
Guys can anyone tell me water from which pathway(apoplastic or symplastic) goes straight through and which stops at the casparian strip

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Good luck everyone. Hope u all do well. I'm going to sleep now :sleep:
Original post by pnaidu
guys, can anyone tell me how many units of DNA are in each stage of the cell cycle, please? :colondollar:


Completely depends on the animal mate

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thanks guys!!
Hi, please can someone help...
You know when you're asked about the loading transport and unloading of oxygen do you write about the pH of CO2 or the p.O2 of oxygen??
Original post by Thebest786
Guys can anyone tell me water from which pathway(apoplastic or symplastic) goes straight through and which stops at the casparian strip

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The apoplastic pathway :smile:

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why is it better to compare base sequences of organisms rather than amino acids? Just because of introns?