Igcse Model Questions Vol1 2017 Biology Question 4

A group of students measured the rate of respiration of germinating broad‑bean (Vigna unguiculata) seeds using a closed‑system respirometer. The set‑up consisted of a sealed container containing 10 seeds, a water‑filled inverted graduated tube (capacity 100 mL) and a temperature‑controlled water‑bath. The change in water level in the graduated tube was recorded for 5 minutes at two different bath temperatures. The volume displaced (ml) for each trial is shown below. | Temperature (°C) | Trial 1 | Trial 2 | Trial 3 | |------------------|---------|---------|---------| | 20 | 12 | 13 | 11 | | 30 | 22 | 24 | 23 | Assume that the volume change is solely due to O₂ consumption (1 mL of water displaced ≈ 1 mL of O₂). Answer the following questions: