Page 16 - 新思维科学活动用书9 样章
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1.2 More about photosynthesis
1 What is the substance that makes leaves green?
2 Explain why Zara’s prediction is likely to be correct.
3 First, Zara put the leaf into boiling water, and left it there for 5 minutes.
Explain why she did this.
4 Next, she took the leaf out of the water and put it into some hot alcohol.
Explain why she did this.
5 Lastly, Zara dipped the leaf into water and spread it out on a white tile. The leaf looked white.
She added iodine solution to the leaf. Some parts of the leaf went orange-brown, and some went
blue-black.
On the diagram below, shade in the parts of the leaf that would go blue-black, if Zara’s
prediction was correct.
6 What substance causes the iodine to turn blue-black?
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