Photosynthesis - Limiting factors

Which line represents the effect of increasing the concentration of carbon dioxide?

• line A

• line B

• line C

The graph shows the rate of photosynthesis at two different carbon dioxide concentrations and at varying light intensities at an optimum temperature of 25^oC.

What factor is limiting at the point indicated 2?

• light

• carbon dioxide

• water

• temperature

An investigation was carried out on the effect of light intensity on the rate of photosynthesis. Throughout the experiment, all other factors affecting photosynthesis were kept constant.

The results are shown on the graph.

What do the results show?

• Light does not limit the rate of photosynthesis.

• Light limits the rate of photosynthesis at point W.

• Light limits the rate of photosynthesis at point Y.

• Light limits the rate of photosynthesis at point Z.

The graph shows the effect of varying light intensity on the rate of photosynthesis.

Which environmental factors could be limiting the rate of photosynthesis between points X and Y?

• carbon dioxide concentration, light intensity and temperature

• carbon dioxide concentration and light intensity only

• carbon dioxide concentration and temperature only

• light intensity and temperature only

The graph shows the rate of photosynthesis against an unknown factor.

What factor is limiting the rate of photosynthesis as shown in the graph?

• carbon dioxide concentration

• number of chloroplasts

• light intensity

• temperature