Biology 9700 · AS & A Level · Testing for biological molecules

Testing for biological molecules — practice question

A student carried out Benedict’s test on four different concentrations of glucose solution and then noted how long it took for the first colour change to appear (the end-point). The student found it hard to spot the exact moment when the colour first changed and always continued timing each solution for two seconds after the colour change had first appeared. This introduced an error into the experiment. Which statements about this error are correct?

  • A1 and 2
  • B1 and 3
  • C2 and 3
  • D3 only

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