BI-741
Factors affecting photosynthesis
Biology · Secondary 3 · Hard · Factors affecting photosynthesis
A leaf is tested for starch after being kept in the dark for 24 hours, then exposed to bright light for 3 hours. Which result best explains the rate of photosynthesis during the 3 hours?
- The leaf turns blue-black with iodine, showing photosynthesis occurred in the light period.
- The leaf stays brown with iodine, showing photosynthesis was fastest in the dark.
- Only the veins turn blue-black, showing photosynthesis occurred only in veins.
- Half the leaf turns blue-black because only old cells photosynthesise.
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