Question

Why are the seeds being boiled in experiments on respiration in the control?

Answer 1

a. It is because only germinating seeds respire aerobically. Oxygen required is taken up from the air of the apparatus. Carbon dioxide released during aerobic respiration is absorbed by potassium hydroxide.

b. KOH is important as it is a good absorber of CO2 and hence absorbs the CO2 that is released by the germinating seeds in the beaker. Due to this, there occurs a vacant space inside the beaker. Hence the water present in the conical beaker receives a suction pull from the beaker and hence tends to go there and so, the water level increases. Hence, the increase in the water level shows that CO2 is formed.