A2 Biology OCR June 2015 Revision Thread

https://docs.google.com/document/d/1sW_toUaWLpw7QcKANIHIUpIHleUwiZjA6nuZEo5-9Lg/edit

There you go.

whoops I didn't even see that! Thank I'll edit now!

I think it's really hard to say

I think grade boundaries for a could be anything from 64-68

I did f215 last year and found it really hard, much harder than this year's paper, and A was 63

I can only see the boundaries increasing for this year

Posted from TSR Mobile

It won't be higher than 65 for an a


Posted from TSR Mobile

That makes sense : I mean if last year's paper is compared with this years then you can see a difference. Last year had a lot of processes and the questions were more straightforward. And there were minimal suggest questions.
This year, there weren't as much as simple questions. Those simple 1 mark questions and just content questions.
Would you say that the grade boundaries will be higher than last years?
It would not be fair, a bit like unit 4. This one was easier but too much suggest, what do you think?

Last years paper wasn't hard, you just had to know the content in depth unlike this year. The long question about transcription and translatingare easy marks as were All the other gene tech questions whereas this year there was less content from the course and more synoptic elements to it. Somrone who learned the spec well would find last year's paper so much easier than this years

That is strange

June 2012 was 67 for an a! And you found that the hardest?

That means this years paper will be like 68/69 for an a
Posted from TSR Mobile

That is so true...there werent many marks that you were confident you knew how to answer. <br />
Do you think the grade boundaries will go lower? lower than last year? because in all fairness last years paper was so much easier, I did it as a mock and it was easy as you just had to write the processes. Yet the grade boundaries were only 63. maybe that says something....??

Difficult to tell. This paper would have benefited a lot of people who didn't learn the content in depth, which would normally be very costly. From that alone, I think it will go up.

For instance, I got an A in the 2014 mock and a friend got. a U and only spent 2 days revising for this exam and it went better for her than me. Why? Because we weren't tested of specific and complex things like the power stroke, muscles or even the nitrogen cycle

yh lool then 9 marker on variations?? is that like 4 QWC marks?

Yeah, the muscles stuff didnt even come up. It was a lot of suggest, again, so we were preparing for being asked on the content but that didnt really come up.<br />
A lot of people on TSR were saying it wasnt great, it was pretty mixed etc. A lot of people at my school said it was a good paper but still more difficult than past papers.<br />
I just don't understand why there were so many suggest questions and not much about the book. If the paper was like 2014 it would have made so much more sense.<br />
Some people are saying it is 65 and stuff. but that doesnt make sense.

In regards to that question I wrote

- Mutation during replication in interphase (1)
- Crossing over in prophase 1 (1) formation of chiasmata (1)
- Independent/random assortment of bivalents in metaphase 1 (1)
- Independent/random assortment of chromosomes in metaphase 2 (1)
- Fertilisation is random (1)

The question also said to wrote about the role of nuclear division so i wrote:
- Meiosis - reduction division - creates gametes/ 4 haploid non-identical daughter cells (1)
- Mitosis - creates 2 identical diploid cells. (1)

- QWC (1)

Hopefully get these 9 marks!!

wasnt the first q meiosis 1 and meiosis 2? and then the next one interphase and anaphase? speaking to people in my year, the answers are mixed but there are a few of the ones ive mentioned.

Oh thanks. Did you have to mention mitosis because I thought the qs was asking about genetic variations

but why would the mass increase after meiosis 1?

the graph increased then decreased. isnt that when bivalents are formed and then during anaphase they split to form 2 cells. then meiosis 2 when the haploid is formed is why the graph decreased from 4 - 1 mass of DNA. ???

Bivalent just means that the homologous chromosomes condense. You should know from unit 1 that DNA replication occurs during interphase, which is when the DNA mass doubles. Why would the mass double during meiosis when division is already occurring?

ok, fair enough. what about the next 2? will interphase (when dna replication occurs) be accepted and part b) anaphase ???