A2 Biology OCR June 2015 Revision Thread

Original post by AKR7

Surely the answers to the first question were meiosis 1 and meiosis 2, as meiosis occurs in the reproductive organs and the question asked about the testes? Also, is there an unofficial mark scheme yet?

Well the second graph showed DNA replication and two cycles of division, which is not simply meiosis 2 as there is no dna replication in meiosis 2

Reply 4783

aoifetully95

1

for the second part of the first question would the answer not have been interphase and telophase cause during interphase dna replicates in prepartion for cellular division and in telophase the sister chromatids reach opposite poles and the nuclear membrane reforms?

Reply 4784

Original post by wanna get laid

What was the reason for the 1:1:1:1 ratio

I said stuff about linkage :dontknow:

Posted from TSR Mobile

Same, which im confident is correct but i only said linkage and not autosomal linkage :frown:

Reply 4785

Original post by aoifetully95

for the second part of the first question would the answer not have been interphase and telophase cause during interphase dna replicates in prepartion for cellular division and in telophase the sister chromatids reach opposite poles and the nuclear membrane reforms?

You're right about telophase processes but at telophase, it's still only one cell and it has not divided to make 2 cells yet, which occurs during cytokineses

Reply 4786

p208134

2

Original post by ChoccyPhilly

Same, which im confident is correct but i only said linkage and not autosomal linkage :frown:

It was a suggest so I said it was due to natural selection. These species have a specific mutation/adaption in their genetic information that allows for them to survive and the absence of it in the other species caused them to die out... I didn't think about linkage :frown:

Reply 4787

Original post by p208134

It was a suggest so I said it was due to natural selection. These species have a specific mutation/adaption in their genetic information that allows for them to survive and the absence of it in the other species caused them to die out... I didn't think about linkage :frown:

Yeah, i definitely think it was a tricky one due to the wording and what you had to process but the fact that you got one or another phenotype far more than the other suggested to me that these genes were inherited together, which made it far more likely to get the genotypes

Reply 4788

Miller_r

1

Original post by p208134

It was a suggest so I said it was due to natural selection. These species have a specific mutation/adaption in their genetic information that allows for them to survive and the absence of it in the other species caused them to die out... I didn't think about linkage :frown:

Yea i also put that at first then when i read the paper again i saw it said genetic reasons,i am really bad at reading questions. When i saw the elk question i first wrote about how the elk are physically bigger because i didn't read the part that said population size i just saw size lol.

Reply 4789

spyrogyra

Anyone creating an unofficial MS?

Posted from TSR Mobile

Reply 4790

Lousamnap

Well i think its safe to say OCR have made real D*CKS out of us!

Reply 4791

Original post by Lousamnap

Well i think its safe to say OCR have made real D*CKS out of us!

I know right. The A2 papers for biology this year have been a joke

Reply 4792

Original post by WishIHadRevised

I think it will be 64 for an A.

Unfortunately, I agree. I'm so annoyed. I put so much work into learning the specification and some other classmates struggled and only learnt half but they thought the exam went better than me cos half of the questions had nothing to do with the specification as it was mostly synoptic! -_-

Reply 4793

Lighfy

Hmm. Paper was very synoptic, but could have been a lot worse I think. *Hopefully* I get my A grade in the summer :s-smilie:

Reply 4794

Ahem-

9

People that resat f212 must have been chuffed with this paper

Reply 4795

Lizzieee4

2

Original post by Hayley Williams

crossing over does occur during cell division...

Yeah I know, someone mentioned something like speciation though

Reply 4796

Lousamnap

Original post by ChoccyPhilly

I know right. The A2 papers for biology this year have been a joke

Yeah Im sitting Chem and physics and aside from physics these papers are totally ridiculous!!!
They are being worded in such a twisted way too!
I'm seriously pissed off with the Exam board , but I'm thinking , they will have to roughly award the same % of A* A B as were achieved at AS otherwise the uni's are going to have a SH*T load of ppl with predicted grades that didn't meet there offers. And that would make the board look inconsistent.
Problem is …. the marks are going to be really skewed …. the papers are looking for to much application and too little time to answer effectively. there is going to be a lot of seriously bright students ending up with marks that don't reflect them accurately.

Reply 4797

Ahem-

9

Original post by Lousamnap

Yeah Im sitting Chem and physics and aside from physics these papers are totally ridiculous!!!
They are being worded in such a twisted way too!
I'm seriously pissed off with the Exam board , but I'm thinking , they will have to roughly award the same % of A* A B as were achieved at AS otherwise the uni's are going to have a SH*T load of ppl with predicted grades that didn't meet there offers. And that would make the board look inconsistent.
Problem is …. the marks are going to be really skewed …. the papers are looking for to much application and too little time to answer effectively. there is going to be a lot of seriously bright students ending up with marks that don't reflect them accurately.

Chem was a real mess

Reply 4798

Lousamnap

Original post by Ahem-

Chem was a real mess

If i Loose my Vet med place i will defiantly consider staging a protest outside
OC... SH*TTY... R

Reply 4799