Igcse Model Questions Vol1 2022 Biology Question 4

You carried out an experiment to compare the rate of respiration in germinating beans kept in light and in darkness. A sealed 50 mL gas syringe was connected to a container holding 5 g of beans. The volume change (increase in gas) was recorded every 5 min for 30 min at a constant temperature of 25 °C. The data obtained are shown. | Time (min) | Volume change – Light (mL) | Volume change – Dark (mL) | |------------|----------------------------|---------------------------| | 5 | 3.2 | 1.8 | | 10 | 6.5 | 3.5 | | 15 | 9.9 | 5.1 | | 20 | 13.1 | 6.6 | | 25 | 16.4 | 8.0 | | 30 | 19.6 | 9.3 | Assume the pressure remains constant and that at 25 °C one mole of gas occupies 24 L. Answer the following questions.