The effect of different substrates on cellular respiration in yeast: practical

Living yeast cells immobilised in alginate beads will carry out cellular respiration and produce carbon dioxide gas. The gas can be collected and the volume of gas measured using an upturned measuring cylinder under water. Identifying independent and dependent variables, and variables to control to increase the validity of the results. How to read the volume of gas from the meniscus in the measuring cylinder after a set time. Collecting repeat measurements for each substrate, and collecting data for different substrates.