Year 12s: what will be the first way you research your future options? >>

A2 Biology OCR June 2015 Revision Thread

Scroll to see replies

Reply 4080

Dark Elixir

Original post by hukdealz

there's rumours circulating that this year is a really easy paper!!!

Come on, where'd you get this info from. I hope to God you're right because I know **** all.

Reply 4081

doctor_2_be

Original post by hukdealz

yep you know it!!
Remember that to make proteins, DNA is converted into messenger (m)RNA as DNA is too large to leave the nucleus. The mRNA acts as instructions for the ribosomes, which produce the protein.

RNA polymerase makes the mRNA from the DNA.

Thanx although that's not what hes referring to apparently. :s-smilie:

What is the extension of PCR?

Reply 4082

doctor_2_be

Original post by ChoccyPhilly

I was referring to the extension stage of PCR...

Haven't got a clue, looks like it's back to the revision guide. :frown:

Reply 4083

ooxbridge

how's everyone revising? past papers or textbook?

Reply 4084

bioevangelist

Original post by doctor_2_be

Thanx although that's not what hes referring to apparently. :s-smilie:

What is the extension of PCR?

Extension of PCR is when Taq DNA polymerase copies the DNA after the primers have annealed. 72ºC....

Reply 4085

hukdealz

Original post by doctor_2_be

Haven't got a clue, looks like it's back to the revision guide. :frown:

PCR is the polymerase chain reaction.
if we want to copy some DNA, we heat it to 95 degrees to separate the strands. Cool it to 55 to allow the primer to anneal. Then heat it to 72 degrees to allow Taq Polymerase to bring free nucleotides and allow the new strand of DNA to be formed.

My advice would be to forget the past papers and focus on revising the specifics from the revision guide. I am willing to bet that this paper will be heavily focussed on just relaying information rather than exam technique focussed questions.

Reply 4086

Meesh14

Original post by ooxbridge

how's everyone revising? past papers or textbook?

just highlighting notes and using a whiteboard to check i know and remember stuff tbh an all nighter for me

Reply 4087

ooxbridge

Original post by Meesh14

just highlighting notes

cool, might start doing that as doing past papers seems a bit pointless, it's not like they ask the same questions each year :\

Reply 4088

Meesh14

Original post by ooxbridge

cool, might start doing that as doing past papers seems a bit pointless, it's not like they ask the same questions each year :\

i find that for bio theres no point in doing past papers cos its better to perfect your knowledge so you can apply it cos all papers this year are applied

Reply 4089

ooxbridge

Original post by Meesh14

i find that for bio theres no point in doing past papers cos its better to perfect your knowledge so you can apply it cos all papers this year are applied

yeah, it's just that I still have a whole stack of questions to get through and I feel kinda guilty just leaving them, but you're absolutely right :smile:

good luck tomorrow btw ^.^

Reply 4090

Ahem-

Original post by doctor_2_be

Thanx although that's not what hes referring to apparently. :s-smilie:

What is the extension of PCR?

Also called annealing.

Reply 4091

Meesh14

Original post by ooxbridge

yeah, it's just that I still have a whole stack of questions to get through and I feel kinda guilty just leaving them, but you're absolutely right :smile:

good luck tomorrow btw ^.^

same here i have 7 papers printed out and they're just sitting there but i have to actually finish revising before i can touch them. lol its not tomorrow anymore, only 9 hours away :O thanks anyway, you too

Reply 4092

mushyD

Everyone go to sleep and wake up at 6. Thats what im doing anyway I cant take this ****

Reply 4093

Meesh14

Original post by mushyD

Everyone go to sleep and wake up at 6. Thats what im doing anyway I cant take this ****

oh i wish i could

Reply 4094

hukdealz

okay we're getting there

on the brain!

Reply 4095

domcandrews

Original post by hukdealz

listen here my ni gga, you know my name not my story. I'm from the hood my nig. Trust me, if you want beef, I'll give it to ya. You don't wanna **** with me.

Yea safe g

Reply 4096

RichBitch

Original post by Eleanorb97

I would say briefly go over the wishy washy chapters like ecosystems, as a lot of it is common sense. Definitely go over genetics! It's such a big chapter there is bound to be multiple questions on it. I'm going through past papers and looking up the questions/topics I really get stuck on, good luck!!!