AQA A2 BIOL5 22nd June 2012

Everyone, just want to ask a question. You know the microscope question, there seems to be answers of either magnification 3046 or 30455.

I personally put 30455, because one sarcomere= 6.7cm = 67mm = 67000micrometres.

Hence magnification = 67000/2.2 = 30455 as enlargement divided by actual.

Therefore, isnt this the right answer?

I was so tempted to add that into my shapes essay XD

would i lose a lot pf marks on the bacteria essay if i talked about

carbon cycle
nitrogen cycle, mutualistic and free-living bacteria, farmers growing legumes to replenish soil nitrogen
in vivo gene cloning and touched on fermenter usage
horizontal gene transmission and antibiotic resistance if you let bacteria with resistant genes escape from your gene cloning
cholera, effect, consequence and treatment
lactose intolerance and its humorous but serious effects
ruminants like cows and sheep and mutualistic relationship with bacteria in stomach
wrote a sentence mentioning mrsa and other bacterial diseases and talked briefly about mrsa being a superbug since it's resistant to methicillin which is a very strong antibiotic

tuberculosis, method of transmission BUT mixed it up with fibrosis when i talked about how it affects lungs, and i forgot to mention eutrophication completely...

im quite nervous about results of this exam because aqa makes unpredictable mark schemes and I need an A in this paper at the very least

why would you lose marks? what else can you seriously but i put exactly the same but i chose 3/4 areas like TB Cholera but expanded my points on them rather then trying to include loads of different little points!

lolll legendary.... I wrote about enzymes ( absolutely raped that topic) and also found my self talking about DNA- how the bases fit together- A only bonds with T and G only bonds with C and that the structure of DNA gives it stability, strength, etc and how important it is to be uncorrupted. Tbh I think I ran out of ideas, expecting about 16-17 out of 25...but couldn't really come up with much more interesting things... What else did you write about?

I wrote about proteins, how they are formed from amino acids and how the amine group of one amino acid joins to the carboxyl group of another and I drew an amino acids (chemical structure). I then wrote about enzymes and gave an example. I went on to talk about photosynthesis, I know this seems weird but I could remember it so I went with it. I mentioned how in the light dependent reaction when the carrier enzyme takes up electrons they're shapes must fit. Then I mentioned the light dependent reaction and drew the Calvin cycle and mentioned how carbon dioxide fits with ribulose biphosphate due to their shapes etc. Then I mentioned muscle contraction in animals and topped it with active transport both in animals i.e establishing a resting potential and in plants when they draw ions up form the soil. I'm hoping for about 20-22 marks. *fingers crossed*

ouchhh... I cant believe I forgot muscle contraction...instead I stayed with enzymes and tried to apply that to as many scenarios as I could, so although I talked about the krebs cycle- I talked about the enzymes involved in it and how they must be a specific shape... and how they're needed to make pyruvate.

For the bacteria essay, would talking about these topics, in a lot of detail, and relating a lot to the title be enough to get high marks?

Unit 1: TB
Unit 1: Cholera
Unit 4: Nitrogen Cycle
Unit 5: In Vivo Gene Cloning

I also had Antibiotic Resistance in my plan but didnt include it in the essay.

Thanks.

I did exactly the same as you! i mean exactly the same! same topics discussed in detail with antibiotic resistance in plan. I think we should do fine because remember its 3 marks for breadth of knowledge they won't like it if we do loads of topics but in little detail because its 16 for scientific content and accuracy so that covers detail ect! So hopefully I think its fine

With luck, I think I've got around 65-70 marks in this paper, which would have been an A last year, but a lot of people seem to think the boundary will probably move up this time. Do you think it'll go above 70? I really need at least a high B in this and I'm really worried that I'll have missed out.

I don't really see it going above 70, seeing as the lowest was 63 and highest 65. However, i do think it could be slightly higher than previous years (maybe 66-68? random guess :P)

anyone got a link to the paper?