Practise identifying the limiting factor from graph gradients, plateaus and paired conditions, then justify whether light, carbon dioxide or temperature constrains the rate.
A student investigated the effect of light on photosynthesis in algae, using hydrogencarbonate indicator solution.
Carbon dioxide is an acidic gas.
Table 4.1 shows the colour of the hydrogencarbonate indicator solution at different pH values.
Table 4.1
Fig. 4.1 is a graph showing the effect of light intensity on the rate of photosynthesis.
Fig. 4.1
State which factors could be limiting the rate of photosynthesis at X and at Y in Fig. 4.1.