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OFFICIAL OCR A2 Biology - F214 Thread

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uer23
Well we were told about this. Not sure if it's the OCR Heinemann Book or not.

The bigger the diameter means the faster the conduction. This is because resistance to the flow of electrical current is inversely proportional to the cross-sectional area of a conductor (like the axon). As an analogy, think of how a wide hose offers less resistance to the flow of water than a narrow hose does. Similarly, a wide axon provides less resistance to the depolarizing current associated with an action potential than a narrow axon does. Hence, the resulting depolarization can spread farther along the interior of a wide axon, bringing more distant regions of the membrane to the threshold sooner.

You probably don't need to know it in that much detail but you may need to keep this in mind.

ah yes that makes sense (from physics) so non myelination means a smaller cross sectional area? but i thought it was just because it was wrapped with schwann cells, does that decrease the cross sectional area of the axon?
Reply 101
clad in armour
ah yes that makes sense (from physics) so non myelination means a smaller cross sectional area? but i thought it was just because it was wrapped with schwann cells, does that decrease the cross sectional area of the axon?


No they're two unrelated things :smile: obviously they both make an action potential faster but they dont have to happen together
Guys I want to help you guys get good grades aswell, so I compelled for myself and for you guys questions on the major topics such as Respiration/Photosynthesis,
I'm nearly finish with the excretion one as it's fairly short but quite long.
So you no longer have to digg through old paste paper to find the right question for the right topic:smile:
here is it Guys I hope I was helpful and don't forget to rep+ me for this ok:smile:

hey guys becoz the document file exceeds the thestudentroom attachment limit, I'm gonna upload it to mediafire:smile:
the document is MS word 2007, so for those who have 2007 it will look good and not out of place, but for those who have earlier MS word version e.g. 2003 you might've to
arrange it a little bit becoz somehow I opened it on earlier version in my college and the questions looked out of place in some pages. But for those who do ICT this should be no problem as you
know how to fix it:smile:
before i post anything, can any TSR legend/or bot confirm if its ok to upload questions that got from the paperbank and cut and pasted on ms word arranged it according to its topic(all the paper were OCR a.k.a central concepts) ?? if this is ok then i will upload the ms word file for people on here to use it solely to practice for the exam.
Reply 105
Remarqable M
before i post anything, can any TSR legend/or bot confirm if its ok to upload questions that got from the paperbank and cut and pasted on ms word arranged it according to its topic(all the paper were OCR a.k.a central concepts) ?? if this is ok then i will upload the ms word file for people on here to use it solely to practice for the exam.


Since if you did and weren't allowed to all you'd have to do would be remove it.. why not just do it lol...
Remarqable M
before i post anything, can any TSR legend/or bot confirm if its ok to upload questions that got from the paperbank and cut and pasted on ms word arranged it according to its topic(all the paper were OCR a.k.a central concepts) ?? if this is ok then i will upload the ms word file for people on here to use it solely to practice for the exam.


Yeah I'm sure this is allowed. They do it in the A Level Past Papers Thread, so why wouldn't it be allowed here.
AnniG
Since if you did and weren't allowed to all you'd have to do would be remove it.. why not just do it lol...


ok if it is soo, here is it guys you first need to download it from mediafire:smile: becoz the file is about 2.20mb exceeds thestudentroom limit

don't forget to rep+ :biggrin:

Photosynethsis: http://www.mediafire.com/?1tnymydn5vt

Respiration: http://www.mediafire.com/?lngjzywlzzt

Homeostasis: http://www.mediafire.com/?53nwmnmwiwz

Excretion: http://www.4shared.com/file/202484260/1cd174d7/Kidney__-_Excretion.html


You do need Microsoft office 2007 to view it properly, otherwise you will have to sort out the questions if its out of place in the older Ms versions.:smile:
i believe this should be no problems for IT geeks lol

don't forget to tell me what you think of my post ok:P
Liverpool F.C.™
Yeah I'm sure this is allowed. They do it in the A Level Past Papers Thread, so why wouldn't it be allowed here.


ok you seem to know the rules well:smile:
Good Luck Everyone:smile:
Remarqable M
ok if it is soo, here is it guys you first need to download it from mediafire:smile: becoz the file is about 2.20mb exceeds thestudentroom limit

don't forget to rep+ :biggrin:

Photosynethsis: http://www.mediafire.com/?1tnymydn5vt

Respiration: http://www.mediafire.com/?lngjzywlzzt

Homeostasis: http://www.mediafire.com/?53nwmnmwiwz

Excretion: http://www.mediafire.com/?mtngntoywtr

You do need Microsoft office 2007 to view it properly, otherwise you will have to sort out the questions if its out of place in the older Ms versions.:smile:
i believe this should be no problems for IT geeks lol

don't forget to tell me what you think of my post ok:P



Thank you so much! Do you have the mark schemes as well
Reply 111
ameliarainbow1
Thank you so much! Do you have the mark schemes as well

This is great and has all the mark schemes thanks alot.
Remarqable M
ok if it is soo, here is it guys you first need to download it from mediafire:smile: becoz the file is about 2.20mb exceeds thestudentroom limit

don't forget to rep+ :biggrin:

Photosynethsis: http://www.mediafire.com/?1tnymydn5vt

Respiration: http://www.mediafire.com/?lngjzywlzzt

Homeostasis: http://www.mediafire.com/?53nwmnmwiwz

Excretion: http://www.mediafire.com/?mtngntoywtr

You do need Microsoft office 2007 to view it properly, otherwise you will have to sort out the questions if its out of place in the older Ms versions.:smile:
i believe this should be no problems for IT geeks lol

don't forget to tell me what you think of my post ok:P


Could you email me the excretion file- the others work but it won't let me download that one...
Edit: dw it works now.
ameliarainbow1
Thank you so much! Do you have the mark schemes as well



You're welcome:smile: and hey don't forget to rep+ me ok:biggrin:
Reply 114
Thanks for the questions Remarqable M :biggrin:
Reply 115
Remarqable M
You're welcome:smile: and hey don't forget to rep+ me ok:biggrin:


Thanks Remarqable but I cant download the excretion file :s-smilie: Do you mind emailing to me (pming you) or reuploading it.
thank goodness i've finally found a thread for this exam !!
arghhhh i can't believe how much there is to learn for just 30% aparrently? especially considering how many important processes there are which go into so much detail i.e. respiration and photosynthesis!
crazy times.
i'm probably having the most difficulty with understanding the hairpin countercurrent multiplier bit, like with the movement of salts across and all that crap, so confusing!!
also understanding non-cyclic photophosphorylation, it's so badly explained. i thought the electrnos moving along the electron carriers was to pump hydrogen ions into the thylakoid space but in the book all it bangs on about is how the energy is needed to make ATP and to reduce NADP...weird.
whoever posted those past paper questions is a god!!!
i have to do well in this exam, as overall for AS i got 239/300 which is one off an A, HOW FRUSTRATING IS THAT!???

haha good luck everyone :smile:
Reply 117
camsterhamster
thank goodness i've finally found a thread for this exam !!
arghhhh i can't believe how much there is to learn for just 30% aparrently? especially considering how many important processes there are which go into so much detail i.e. respiration and photosynthesis!
crazy times.
i'm probably having the most difficulty with understanding the hairpin countercurrent multiplier bit, like with the movement of salts across and all that crap, so confusing!!
also understanding non-cyclic photophosphorylation, it's so badly explained. i thought the electrnos moving along the electron carriers was to pump hydrogen ions into the thylakoid space but in the book all it bangs on about is how the energy is needed to make ATP and to reduce NADP...weird.
whoever posted those past paper questions is a god!!!
i have to do well in this exam, as overall for AS i got 239/300 which is one off an A, HOW FRUSTRATING IS THAT!???

haha good luck everyone :smile:

i was 2 marks of an A was so gutted !
ive just tried to learn the ocr textbook and practise past papers .....does anyone how much synoptic questions were likely to get.
alsooo can someone PLEASE explain to me this:
in the photosynthesis module, there's a double spread about limiting factors, and basically all i can figure out is that carbon dioxide, light and water levels all increase photosynthesis rate? what else do we need to know form that double spread? seriously like, i have no clue what else that spread talks about? so confusing? what do we need to knowww !!
camsterhamster
alsooo can someone PLEASE explain to me this:
in the photosynthesis module, there's a double spread about limiting factors, and basically all i can figure out is that carbon dioxide, light and water levels all increase photosynthesis rate? what else do we need to know form that double spread? seriously like, i have no clue what else that spread talks about? so confusing? what do we need to knowww !!


OCR A Level Biology Specification (Go to Page 34)

Tells you what you need to learn for that part.

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