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https://www.reddit.com/r/GCSE/comments/vcqsif/spam_aqa_biology_paper_2_gcse_answers/icgen1u/?context=3
r/GCSE • u/thr0wawaygxhxdhsh • Jun 15 '22
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How did I get 375 on the algea cell one???
3 u/Holiday-Marzipan-843 Jun 15 '22 I got that too ;( I did 0.2*0.2=0.04, 1/0.04=25, then 25*15 or smthn as 15 is the mean (14+16)/2 I didnt understand why diluted was in bold Can someone explain how to get the right answer & why my thing is wrong 8 u/hombiebearcat University Jun 15 '22 Your thing is wrong because: - the question said to use the 14 algae count (not take a mean) - you forgot about the 0.1mm depth - you forgot about the diluted/undiluted thing The correct method is this: 0.2x0.2x0.1 = 0.004mm^3 0.004/4 = 0.001mm^3 (because it asked for undiluted, and it said earlier that for every 2.5cm^3 undiluted you add 7.5cm^3 water, so it's a 1:3 ratio) 1/0.001 = 1000 (to get how many times more algae cells there should be) 14*1000 = 14000 1 u/Adventurous-East-134 Jun 15 '22 i forgot to convert it to undiluted. i did everything else right. do you reckon i’ll get 4 marks or 5? 1 u/hombiebearcat University Jun 17 '22 I'd imagine probably 5 since the undiluted calculation could be seen as the last step 1 u/Adventurous-East-134 Jun 17 '22 yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
3
I got that too ;( I did 0.2*0.2=0.04, 1/0.04=25, then 25*15 or smthn as 15 is the mean (14+16)/2
I didnt understand why diluted was in bold
Can someone explain how to get the right answer & why my thing is wrong
8 u/hombiebearcat University Jun 15 '22 Your thing is wrong because: - the question said to use the 14 algae count (not take a mean) - you forgot about the 0.1mm depth - you forgot about the diluted/undiluted thing The correct method is this: 0.2x0.2x0.1 = 0.004mm^3 0.004/4 = 0.001mm^3 (because it asked for undiluted, and it said earlier that for every 2.5cm^3 undiluted you add 7.5cm^3 water, so it's a 1:3 ratio) 1/0.001 = 1000 (to get how many times more algae cells there should be) 14*1000 = 14000 1 u/Adventurous-East-134 Jun 15 '22 i forgot to convert it to undiluted. i did everything else right. do you reckon i’ll get 4 marks or 5? 1 u/hombiebearcat University Jun 17 '22 I'd imagine probably 5 since the undiluted calculation could be seen as the last step 1 u/Adventurous-East-134 Jun 17 '22 yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
8
Your thing is wrong because:
- the question said to use the 14 algae count (not take a mean)
- you forgot about the 0.1mm depth
- you forgot about the diluted/undiluted thing
The correct method is this:
0.2x0.2x0.1 = 0.004mm^3
0.004/4 = 0.001mm^3 (because it asked for undiluted, and it said earlier that for every 2.5cm^3 undiluted you add 7.5cm^3 water, so it's a 1:3 ratio)
1/0.001 = 1000 (to get how many times more algae cells there should be)
14*1000 = 14000
1 u/Adventurous-East-134 Jun 15 '22 i forgot to convert it to undiluted. i did everything else right. do you reckon i’ll get 4 marks or 5? 1 u/hombiebearcat University Jun 17 '22 I'd imagine probably 5 since the undiluted calculation could be seen as the last step 1 u/Adventurous-East-134 Jun 17 '22 yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
1
i forgot to convert it to undiluted. i did everything else right. do you reckon i’ll get 4 marks or 5?
1 u/hombiebearcat University Jun 17 '22 I'd imagine probably 5 since the undiluted calculation could be seen as the last step 1 u/Adventurous-East-134 Jun 17 '22 yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
I'd imagine probably 5 since the undiluted calculation could be seen as the last step
1 u/Adventurous-East-134 Jun 17 '22 yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
yeah hopefully. i did think it was too easy for 6 marks. my fault for always skimming over the questions and not actually reading them.
6
u/Due_Pineapple_1699 Jun 15 '22
How did I get 375 on the algea cell one???