Neco Model Questions Vol1 2017 Biology Question 4

A group of students is studying the effect of temperature and a metabolic inhibitor on the rate of respiration in germinating beans using a closed‑system respirometer. The procedure is as follows: 1. Place 10 germinating beans in the respirometer chamber containing 50 ml of water. 2. Connect the chamber to a graduated tube filled with water; the displaced water volume indicates the amount of CO₂ produced. 3. Record the volume of displaced water after 5 min at three different temperatures (the water bath is allowed to stabilise before each measurement). The data obtained are: - 20 °C : 12 ml displaced - 30 °C : 18 ml displaced - 40 °C : 30 ml displaced 4. After the 30 °C measurement, a drop of potassium cyanide solution (a known inhibitor of cytochrome oxidase) is added to the chamber and the experiment is repeated at 30 °C. The displaced volume after 5 min is 6 ml. Answer the following questions: