Explain why light intensity may act as a limiting factor in photosynthesis.
The concentration of carbon dioxide ($\text{CO}_2$) may also limit photosynthesis. It affects the Calvin cycle in the light-independent stage of photosynthesis. Ribulose bisphosphate (RuBP), triose phosphate (TP) and glycerate 3-phosphate (GP) are three key molecules in the Calvin cycle. Fig. 2.1 illustrates how the concentration of GP changes when the concentration of $\text{CO}_2$ is lowered from $0.04\%$ (atmospheric) to $0.008\%$. Complete Fig. 2.1 by drawing the lines for RuBP and TP when the concentration of $\text{CO}_2$ is lowered from $0.04\%$ to $0.008\%$.
In very dry conditions, $\text{CO}_2$ concentration can become the main limiting factor of photosynthesis in plants. Explain how very dry conditions make $\text{CO}_2$ concentration the main limiting factor of photosynthesis in plants.
Calculate the percentage change in mean plant biomass when Sox4 plants are compared with wild type plants. Show your working.
Suggest and explain why Sox4 plants show a different mean plant biomass from wild type plants.
Some soils may be low in nitrates. Suggest how nitrate deficiency could limit the quantity of SBPase made by Sox4 plants.
Suggest and explain why Sox4 plants show a different mean plant biomass from wild type plants.
Some soils may be low in nitrates. Suggest how nitrate deficiency could limit the quantity of SBPase made by Sox4 plants.