Question

Use the information provided and your knowledge of the light-independent reaction to explain why the yield from soya bean plants is decreased at higher concentrations of oxygen. Phosphoglycolate is not used in the light-independent reaction. (3)

a) Higher oxygen levels increase the rate of photosynthesis, leading to lower yields in soya beans.
b) High oxygen concentrations inhibit the action of ribulose bisphosphate and reduce carbon dioxide fixation during the Calvin cycle.
c) Soya bean plants do not respond to changes in oxygen levels, so the yield remains the same.
d) Phosphoglycolate is a competitive inhibitor of oxygen in the light-independent reaction.

Answer 1

Higher oxygen concentrations inhibit the action of ribulose bisphosphate and reduce carbon dioxide fixation during the Calvin cycle, resulting in decreased yield in soya bean plants.

Step-by-step explanation:

Higher oxygen concentrations inhibit the action of ribulose bisphosphate and reduce carbon dioxide fixation during the Calvin cycle. This leads to a decrease in the yield from soya bean plants at higher concentrations of oxygen. Although phosphoglycolate is not used in the light-independent reaction, it is worth noting that phosphoglycolate is a competitive inhibitor of oxygen in the light-independent reaction.