Practice Questions

1.State two ways that we can measure the rate of photosynthesis

1.Counting oxygen bubbles released by pondweed per minute

2.Measuring the volume of oxygen produced using a gas syringe

2. A graph is plotted using volume of oxygen gas produced against time. Suggest how the rate of photosynthesis can be measured and calculated at a specific point in time

The gradient of the line will represent the rate of photosynthesis. 

Draw a tangent to the line, calculate the gradient of the line. 

3. In the diagram of the experiment above a tank of water is placed between the lamp and the pond weed. Suggest the role of the water tank.

The tank of water absorbs the heat energy of the lamp, but allows light energy to pass through the water. 

As temperature is a limiting factor for photosynthesis, it needs to be controlled, otherwise it will affect the results of the experiment.