PolyToday: Photosynthesis

Eighth-graders recently took on a classic photosynthesis investigation. Using Bunsen burners, the students boiled a destarched leaf to remove the waxy cuticle, heated it in ethanol to remove chlorophyll, and then tested it with iodine solution. The big reveal came quickly: only the parts of the leaf that received light turned blue-black, indicating the presence of starch and proving that light is needed for photosynthesis.