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AQA A Level Biology Recombinant DNA Tech

Reply 1


Use the graph to find C. You can assume that the maximum fluorescence occurs when there is maximum DNA concentration.
The maximum fluorescence on the graph is approximately 0.48, meaning that 50% of this is 0.24.

Follow the X axis where Y=0.24 (approx.) to until you intercept curves A and B, to find the number of cycles required (C)
For A you find that C = 19 (approx.)
For B you find that C = 27 (approx)

RNA in a sample = 1/C
RNA in sample A = 1/19 = 0.05263...
RNA in sample B = 1/27 = 0.03704....

to find the ratio:
0.05263 / 0.3704 = 1.42...
Ratio of RNA in A:B = 1.4:1

Hope that helps :smile:
(edited 10 months ago)

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