If a dormant seed absorbs water, germination starts and its respiration rate rises. Name the plant growth regulator that triggers the start of seed germination.
Give the function of potassium hydroxide solution when a respirometer is used.
As respiration occurs, oxygen is taken up by the seeds and the coloured liquid moves down the tube. Describe the function of oxygen in aerobic respiration.
Respirometers, as shown in Fig. 8.1, were used to study how temperature affected the respiration rate of germinating pea seeds.
Suggest a reason for leaving the respirometers for 10 minutes before taking measurements.
Suggest why respirometers B and D were included in this investigation.
Calculate the rate of oxygen uptake in $\text{cm}^3$ per minute for respirometer C between 5 and 20 minutes. Give your answer to two significant figures. Show your working.
Explain why the respiration rate of germinating pea seeds increases between $10\,^{\circ}\text{C}$ and $25\,^{\circ}\text{C}$.
Suggest why carrying out the experiment with germinating seeds at $50\,^{\circ}\text{C}$ may produce a lower respiration rate than at $25\,^{\circ}\text{C}$.