A2 Biology OCR June 2015 Revision Thread

predictions?

This is what i've heard people have been saying and what i think hasn't come up for a while:

galapagos,
something out of the topic about pcr/genome sequencing/insulin/rice etc,
something out of the pages 232, 236-237 (muscles topic),
brain
shedding leaves (pg 223)
how auxins stimulate shoot growth (pg 222)
meiosis
apoptosis
epistasis
something out of the topic animal behaviors (social behavior in primates i think)
Chi squared
Nitrogen cycle
Aseptic technques/Asepsis - that table on the bottom of pg 163

but anything could come up :frown:

even repeated topics

Reply 3781

peanutcracker20

2

can anyone teach me muscle contractions its so confusing and its bound to come up

Reply 3782

Diamond Crafter

8

Original post by peanutcracker20

PSYA4r which was also two hours long, been up since five this morning so its a rough day

Aye, it has been a long one. Although I'm sure we'll all get through to the end if the countless number of previous year 13s before us could. :wink:

Reply 3783

flowerbud

8

Can anyone explain to me Chi-squared? I understand how to use the equation etc.. but the hypothesis confuses me. If X^2 is less than 0.05 (5%) do you accept or reject the null hypothesis, and what does this mean in terms of your experimental data being down to chance or being significant....

it confuses me so much!!!

Reply 3784

bakedbeans247

20

Original post by BioAgent

Yh just found out 18th. All nighter it is.

Lol. Well i'd say get at least 5-6 hours sleep bro! Hopefully we'll smash this exam! iA.

F215 :whip:

Reply 3785

Lizzieee4

2

How much detail do we need to know the nitrogen cycle in? There's a massive diagram in the textbook, do we need to know that or just the roles of the bacteria? (Do we need to know all of the haber process, Urea -> ammonium etc)

Reply 3786

lyd.maddox

7

Original post by tewas

Anybody have any questions they want answered?

what are the steps involved in sequencing the genome of an organism?
How does gene sequencing allow for genome-wide comparisons between individuals and between species? :smile:

Reply 3787

Yua

14

well im ****ed ive had too many exams to revise for

Reply 3788

bakedbeans247

20

Original post by flowerbud

Can anyone explain to me Chi-squared? I understand how to use the equation etc.. but the hypothesis confuses me. If X^2 is less than 0.05 (5%) do you accept or reject the null hypothesis, and what does this mean in terms of your experimental data being down to chance or being significant....

it confuses me so much!!!

This guys explains it well (from the ocr book too)! Pretty easy when you understand it:
https://www.youtube.com/watch?v=fB03aPk_wxA

Reply 3789

Diamond Crafter

8

Original post by bakedbeans247

x

To be fair, I think last years paper wasn't too atrocious and a lot of the topics now having done revision are easier so if repeated topics do come up then surely that's a win-win? :redface:

Orite m8

Original post by peanutcracker20

oh god, good luck in both would hate to being doing both so close together thought just biology is bad enough

Not even sure luck can save me anymore fml

Reply 3792

Mousyy

3

Well I'm not getting any sleep today cause I'm no where near prepared for this exam as I should be hears to the crammers, btw does anyone have predictions for tomorrow?

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Reply 3793

doctor_2_be

3

Original post by Saltedcaramel1

Still haven't done June 14 argh

I haven't done any of the papers yet.

Trying to cram as much as possible then do 2 past papers at least so ur in a much better position than me :angry:

Reply 3794

Mousyy

3

Original post by Yua

well im ****ed ive had too many exams to revise for

Same all the unit 4s for my subjects have been this week :frown:

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Reply 3795

Cdp3

2

Original post by Yua

well im ****ed ive had too many exams to revise for

SAME

Exactly the problem i'm facing atm

Reply 3796

doctor_2_be

3

Original post by Lizzieee4

How much detail do we need to know the nitrogen cycle in? There's a massive diagram in the textbook, do we need to know that or just the roles of the bacteria? (Do we need to know all of the haber process, Urea -> ammonium etc)

****!! I forgot all about that

In this rate I won't even get any past papers done

Reply 3797

Mousyy

3

Original post by doctor_2_be

I haven't done any of the papers yet.

Trying to cram as much as possible then do 2 past papers at least so ur in a much better position than me :angry:

Out of curiosity cause I'm in the same position as you rn (i have done some past papers tho) are you making notes or jist going through the book I've literally lost all faith in this exam

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