OCR Biology A Exam Thread (Breadth - May 26, 2016 and Depth - June 7, 2016)

Reply 1040

adeninesbff

3

Original post by Desouza123

We don't have to know the Chi-Squared test. It's not on the spec.

THANK YOU! It's just everyone has been talking about it and I have no idea whether it is coming up or not.

Reply 1041

violavenisis

3

Original post by mm_7

no i meant once its has binded to the allosteric site of the enzyme does it ever 'unbind' or does it stay in the allosteric site permanently?

No, it can unbind from the allosteric site. However, because they are always present they prevent you from reaching Vmax, as there is a chance that at least one is currently bound to an enzyme (which is why the graph for non-competitive inhibition does not level off at the same point as the standard graph).

Reply 1042

mxhxs_101

9

Original post by violavenisis

No, it can unbind from the allosteric site. However, because they are always present they prevent you from reaching Vmax, as there is a chance that at least one is currently bound to an enzyme (which is why the graph for non-competitive inhibition does not level off at the same point as the standard graph).

ohhh! thanks; that was soo much clearer!

Reply 1043

violavenisis

3

Original post by mm_7

ohhh! thanks; that was soo much clearer!

No problem- just remember that you can get inhibitors that are irreversible (for example, organophosphates in insecticides/herbicides). Our spec doesn't really cover these in great detail, so usually assume that the inhibitor that they are talking about is reversible, unless stated otherwise.

Reply 1044

mxhxs_101

9

Original post by violavenisis

No problem- just remember that you can get inhibitors that are irreversible (for example, organophosphates in insecticides/herbicides). Our spec doesn't really cover these in great detail, so usually assume that the inhibitor that they are talking about is reversible, unless stated otherwise.

oh, ok thanks!

Reply 1045

jemmaveness1

5

anyone got a mark scheme for vbreadth paper?

Reply 1046

bastille1789

does anyone have a list of all the PAGS that we need to know for this exam?and please could any of you link me any useful docs or resources with possible PAG questions and answers

Reply 1047

ultralightbeam

1

does anyone know where i can find topic questions on fish and insect gas exchange

Reply 1048

Internets

5

Original post by Desouza123

We don't have to know the Chi-Squared test. It's not on the spec.

Original post by adeninesbff

THANK YOU! It's just everyone has been talking about it and I have no idea whether it is coming up or not.

http://www.ocr.org.uk/Images/171693-specification-accredited-as-level-gce-biology-a-h020.pdf <= Is this the right spec?
On page 48 is says 'Learners may be tested on theirability to select and use:• the chi squared test to test(χ2) the significance of thedifference between observedand expected results• the Student’s t-test• the Spearman’s rankcorrelation coefficient'

I'm a bit confused because we haven't even touched this formula for the whole year, so maybe it isn't required anymore.

(edited 7 years ago)

Reply 1049

haes

6

has the secured specimen paper 2 been posted on this thread? if so which page?

Reply 1050

Desouza123

2

Original post by Internets

http://www.ocr.org.uk/Images/171693-specification-accredited-as-level-gce-biology-a-h020.pdf <= Is this the right spec?
On page 48 is says 'Learners may be tested on theirability to select and use:• the chi squared test to test(χ2) the significance of thedifference between observedand expected results• the Student’s t-test• the Spearman’s rankcorrelation coefficient'

I'm a bit confused because we haven't even touched this formula for the whole year, so maybe it isn't required anymore.

I'm not too sure but the official textbook only has SD, Ttest and spearmans rank

Reply 1051

jossawdry

1

In a matter of urgency, does anyone have the breadth or depth practice papers.......

Reply 1052

millymolly123

2

Hi does anyone have any depth past papers?

Reply 1053

Internets

5

Original post by Desouza123

I'm not too sure but the official textbook only has SD, Ttest and spearmans rank

That's so weird. It might be a good idea just to be safe a learn it. It won't take long and if it comes up, it could be worth like 3 marks.

Reply 1054

ImagineCats

19

so tomorrow is my last chance of getting a D RIP me

Reply 1055

Jordd111

Anyone know what they think will come up in the depth exam tomorrow based on the first exam?

Reply 1056

Ozil5

8

We've been told that chi squared is needed and it does say it is required on the spec. But I just learnt it now for the first time and it doesn't take too long so I'd recommend learning it anyway.

Also, is the highest amount of marks for a single question 6 under the new spec?

Thanks!

Reply 1057

skwonc

1

I've completely failed every exam ive taken and im panicking so so so much for tomorrow oh my god

Reply 1058

skwonc

1

Original post by Ozil5

We've been told that chi squared is needed and it does say it is required on the spec. But I just learnt it now for the first time and it doesn't take too long so I'd recommend learning it anyway.

Also, is the highest amount of marks for a single question 6 under the new spec?

Thanks!

Thanks but what on earth is chi squared? googled and still dont get it..