AQA A-Level Biology (7402) Exam Thread - June 12th, June 20th and June 26th

Got a feeling proteins will come up as the essay. There's enough in the spec on them and I don't think I've seen a proteins essay question.

ultrafiltration is used in the context of kidneys, not tissue fluid.

can someone help me please:
1. i know npp = gpp - r and npp is the energy avaliable for growth, reproduction and the next trophic level, but where about would atp energy come in? is it part or npp, as it isnt lost as heat during respiration but is formed..

2. for plant growth, do plants grow by forming atp from respiration and using this for growth, or by making polysacharrides from things like photosynthesis?

Hey all,

A good resource for those of you wanting 'predictions' of what might come up on the next two papers is this document;

http://www.aqa.org.uk/resources/science/as-and-a-level/biology-7401-7402/plan/summary-of-changes.

It outlines the changes made to the spec, and it's probably a safe bet to say that AQA are likely to ask questions on brand new content, just so they can justify putting it into the spec. Of course, that's not to say we should only revise what's in that document, but maybe make sure you know everything there in enough detail. Hopefully we don't get any more nasty surprises 😭

Good luck all!

Cheers, that's a good idea


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1. GPP = "total quantity of chemical energy STORE in biomass". ATP isn't really stored, its an immediate energy source-it breaks down very quickly (ok its stored for like a few seconds but that doesn't really count). When it breaks down part of the energy is coupled to other cell processes (e.g Active transport) and the rest IS released as heat, so i'd argue the remainder of ATP's energy IS lost as heat.

2. Plants photosynthesise to form organic products (which can be used for growth). They also use organic products formed from photosynthesis in respiration to produce ATP which is used for cell division etc. so growth, I would say, involves both processes.

Good call... that would be a good one too as lots of different topics


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Plus very little of proteins on paper 1 I can't even remember if proteins were involved in paper one at all??

does anyone know if we need to know about photosystems??

yh so ps2 absorbs light frequency of 700nm and ps1 is 680nm and ps2 and ps1 involved in cyclic light dependent but only ps1 in non cyclic and in non cyclic an electron acceptor is also used

does anyone know if we need to know about photosystems??

do we need to know about replica plating in detail?

Guys I'm freaking out. Have any of you looked at the specimen paper 2 on their website? The markscheme doesn't even make sense for some of them. Like, the second question, a) a more logical answer would be that 20C replicates the environment the seed would normally be in and b) 20C is nto the optimal temperature for growth. Like, what's even the point o ftrying to think when the answers don't even make logical sense?