BIOL4 Biology Unit 4 Exam - 13th June 2011

Do our answers have to be word for word with what the markscheme says?

Of course not, but there are certain key words that are required to get a mark, for example, not including 'electrochemical graident' in a photosynthesis/respiration question could lose you a mark as correct terminology is often required.


I usually just chuck every relevant biological term I can think of into a question, for example, its difficult to not get full marks on an enzyme question if you stiick in 'complementary' 'enzyme-substrate complex' and 'specific' in.

Thanks, do you have any tips on how to answer the how science work type questions i always get an answer, think its right and then when i check it the markscheme has an answer that is completely different :/

Look at all the past papers you can, even those from other units and learn the questions and answers they commonly ask, they often recycle.

Learn the definitions of accuracy, precision, reliability, standard deviation and statistically significant.

Why is it important samples are random AVOID BIAS!

Familarise yourself with ratios, percentage increase/decrease, rate of change. Know all the formulas you can, if you know Hardy Weinburg well, a Hardy Weinburg question is a gift, theres no grey areas on the MS with those, its a mark for just working out (even with a wrong answer!) and a mark for the answer.

Why are the masses of apple slices given as a ratio: different starting masses, easy comparision.

Never discount the obvious answer, and always have a go, even if the idea in your head sounds absurd...sometimes AQAs HSW answers are absurd

Jan 2010

In the light dependent reaction of photosynthesis, light energy generates ATP.
Describe how (5 marks)

Light (energy) excites/raises energy level of electrons in
chlorophyll;
2 Electrons pass down electron transfer chain;
3 (Electrons) reduce carriers/passage involves redox
reactions;
4 Electron transfer chain / role of chain associated with
chloroplast membranes / in thylakoids / grana;
5 Energy released / carriers at decreasing energy levels;
6 ATP generated from ADP and phosphate/Pi /
phosphorylation of ATP;

mark scheme dosent specifically mentions proton gradients though. But i dont see no harm in learning it just incase, and its just the same as respiration aint it which we do need to know except for its a thylokoid membrane instead of mitochondria membrane?

I would have spent ages thinking about this and not getting the answer...thanks
Producing say 32 ATP anaerobically need 16 times respiration which produces 32 co2 molecules (which is higher)

Still not sure about 2b tho

hey anyone have a copy of jan 2011 paper???

can anybody help me with question 5b on paper Jan 11? gross rate of photosynthesis!thanks.

lost me completely on that one lol Good luck for tomorrow xxx

Haha
I will need it..am sure u do well xxx


Someone care to explain 7c and 7dii

[URL="http://store.aqa.org.uk/qual/gce/pdf/AQA-BIOL4-W-QP-JAN10.PDF"]http://store.aqa.org.uk/qual/gce/pdf/AQA-BIOL4-W-QP-JAN10.PDF

hold on, 13th is tommorow?

ah crap.

So scared for this exam ... but looking at the AQA grade boundaries they seem pretty low ?!
e.g. 67% raw marks in June 10 would of given you full UMS?!?

thats becuase this exam is a f-ing piss take! The wording of the questions is annoying as well as the HSW. It is a hard exam don't take it lightly! I resitting after getting a D!