On a graph, the rate of photosynthesis rises with light intensity and then levels off. In the levelled-off part,

  1. photosynthesis has stopped
  2. another factor such as CO₂ or temperature is limiting
  3. the plant is dead
  4. light is limiting
Answer

B) another factor such as CO₂ or temperature is limiting

When the graph is flat, light is no longer the limiting factor. O Level Biology · Topic 6 Plant Nutrition · 6.1 Photosynthesis

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