Students investigate yeast respiration by measuring the volume of gas produced at different glucose concentrations. They use a gas syringe connected to a sealed flask containing the yeast and glucose mixture.
Table of Results:
Glucose concentration (%)Volume of gas collected in 10 minutes (cm3)0028415621825 \begin{array}{|c|c|} \hline \text{Glucose concentration (\%)} & \text{Volume of gas collected in 10 minutes (cm}^3\text{)} \\ \hline 0 & 0 \\ \hline 2 & 8 \\ \hline 4 & 15 \\ \hline 6 & 21 \\ \hline 8 & 25 \\ \hline \end{array} Glucose concentration (%)02468Volume of gas collected in 10 minutes (cm3)08152125Identify the independent variable and the dependent variable in this investigation.
Explain why using a gas syringe to measure the rate of respiration is more accurate than counting the number of bubbles of gas released per minute.
Describe the relationship shown by these results between the glucose concentration and the volume of gas collected. Include data from the table to support your answer.
Use the data to estimate the volume of gas that would be collected in 10 minutes if a 5%5\%5% glucose solution was used. Justify your answer.
44 exam-style questions on OCR GCSE Biology Practical skills. Each one has a worked solution and a mark scheme showing where the marks go.