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OFFICIAL OCR A Biology A level Exam Thread- 12th, 20th and 26th JUNE 2017

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pretty close

its a)transpiration pull continuous column of water (cohesion &adhesion)
b) root pressure with the osmosis of water after the medulla is concentrated with minerals with the introduction of the casparian strip.
c) capillary action

well thats what the book says atleast (ocr a bio p217)
correct me if im wrong

Is a actual question if yes please tell where its from

Reply 21

GenuineHpLaptop

Original post by science&maths!!!

Is a actual question if yes please tell where its from

its from the ocra bio a text book p217
theres a heading water movement up stem and a list of 3 processes that cause them.

= probable 6m

Reply 22

FrankJones22

Original post by M0nkey Thunder

The textbook that I used mentioned citrulline and arginine too, so you may want to consider learning that.
Ornithine is converted into citrulline by adding ammonia, carbon dioxide and removing water.
Citrulline converted into Arginine by adding ammonia and removing water.
Arginine converted back into ornithine by adding water; removing urea as a by-product.

Okay, thanks a lot!

Reply 23

DrawTheLine

Original post by FrankJones22

Okay, thanks a lot!

The spec says you only need to know the outline of it. So you may be asked to label the cycle on a diagram

Reply 24

DrawTheLine

I created 3 mnemonics to help me remember the processes of respiration. Posting them in case they are useful:

Glycolysis:
Granny Has Ten Pound Notes
Granny: glucose plus 2 phosphate molecules from ATP combine to create...
Has: hexose bisphosphate which is unstable so splits into...
Ten: two triose phosphate molecules. These are dehydrogenated to create...
Pound: two pyruvate molecules
Notes: NAD accepts the hydrogen ion so becomes reduced NAD

Link reaction:
Paul Dad Dances Amazingly
Paul: pyruvate enters the matrix and is...
Dad: decarboxylated and...
Dances: dehydrogenated to create...
Amazingly: an acetyl group. This is combined with coenzyme A to form acetyl coA

Krebs cycle:
Actors Only Consider Dancing Daftly Not Crazily For Days During Oscars
Actors: acetyl coA is combined with...
Only: oxaloacetate to form...
Consider: citrate which is...
Dancing: decarboxylated and...
Daftly: dehydrogenated to form...
Not: reduced NAD and...
Crazily: carbon dioxide as well as...
For: a 5 carbon compound which is...
Days: decarboxylated and...
During: dehydrognated to regenerate...
Oscars: oxaloacetate and form reduced FAD

Reply 25

stressthistest

ah i hate muscle contraction is it likely to come up?

Reply 26

TheAlphaParticle

Original post by stressthistest

ah i hate muscle contraction is it likely to come up?

Most likely, i'm thinking probably a micrograph question

Reply 27

Pmercer98

wow... well what was that paper? Does anyone have any thoughts? were we meant to know standard deviation formula off by heart?!

Reply 28

TheAlphaParticle

Original post by Pmercer98

wow... well what was that paper? Does anyone have any thoughts? were we meant to know standard deviation formula off by heart?!

That was a piece of **** honestly!! how were we meant to write 6 marks based on just one graph and one sentence!!! Luckily i looked over the stats before the exam even though they weren't meant to be in this exam, just in case OCR decides to flipping cruel

Reply 29

bluegirl64

Personally, I found it horrific :frown:

Reply 30

Henry Davis

i know i was told i did not need to know it, i guessed in the exam and forgot the square root so i got 20 something instead of the square root of that which is probably 4.4 and that cost me about 3 marks i think

Reply 31

Henry Davis

what did everyone put for the podocyte mitosis question?

Reply 32

DrawTheLine

That was f*cking awful. Did anyone else see just a bunch of red blobs on the insert?

Reply 33

cream_pie

Original post by DrawTheLine

That was f*cking awful. Did anyone else see just a bunch of red blobs on the insert?

That insert was a ****ing joke

Reply 34

I.norrington

Yep, I found that absolutely horrendous. So much of it was so difficult that I got thrown on stuff I did know and so made stupid mistakes as well as honest mistakes. Like, I said that plants can't respire anaerobically, what the f*ck was that about? I think that if they weren't going to give us formulas, they really should have made that crystal clear. I will have lost a mark on the volume of a sphere because I did 3/4 rather than 4/3 at the beginning of the formula. Try not to worry too much though (and I'm saying that to myself too!!). I go to a specialist science school and literally everyone found it difficult. Our brother school (we're an all-girls school) also had students that found it impossible. Even the to-be Oxbridge med students found it really hard. Sooooo probably really low grade boundaries. I'm thinking like 65% for an A.