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Julius von Sachs discovered where starch was made in a plant. Emerging microscopy techniques enabled him to see inside plant cells, where he found chloroplasts.

Modern electron microscopes can be used to look at chloroplasts inside living cells, showing them moving around in order to trap the optimum amount of light.
This clip is from:
First broadcast:
14 June 2011

Classroom Ideas

This clip could be used to explain the process of photosynthesis in more detail and to explain the structure of plant cells. The clip is also relevant when looking at the development of microscopy techniques and the types of images generated from light microscopy compared to electron microscopy. If microscopes are available, students could study leaves under them and draw what they see.

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