AQA A-level Biology 7402 - Paper 3 - 17th June 2019 Unofficial Markscheme

yeah you wouldnt have to do a calibration curve, but you would have to make sure the colorimeter is calibrated to a sample of denionised water before testing the river samples

what was the actual answer of the tick box whether it was first or last but the writing??

I wrote this too! I’d say 2/3 marks. I didn’t mention a calibration curve, which probably would’ve been the third mark

can anyone tell me why exactly you need a calibration curve cuz theyre used to work out the relationship with the concentration which in this case is pointless, surely you can just use the calorimeter on it own and just find absorbance and thatll tell you how cloudy they are relative to each other and pure water??????

I blanked on question and put something along the lines of use a coloromiter to measure how much light passes through each sample..

1 mark worthy?

Edit: i also mentioned calibrating it with a sample of clear water

I wrote if they are pregnant. And I wrote if they are on any current medication. Dont know if they are right as you needed both points for the 1 mark

Pretty sure this was a 2 marker? I wrote ethnicity and exercise levels, dunno what would be on the mark scheme tho

Pretty sure this was a 2 marker? I wrote ethnicity and exercise levels, dunno what would be on the mark scheme tho

I think they will be higher than last year. They are going to be like 2017. Bcoz last year the papers were insanely hard so the grades boundaries dropped

I put height and ethnicity i think,...

So like 174 for an A*? Do you think this might increase?

I calculated that my minimum would be about 152 and maximum about 170 (out of 260) What grade would this be 😭

Hey, has anyone found the 2019 past papers online anywhere? Found paper 1 but not 2 or 3.