Please open to page 10.2 and take out a red pen to fix any mistakes.

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We can learn from mistakes.

​Directions

​If starch is found in a Geranium leaf, the process of photosynthesis must have taken place.

1. Suppose starch was found in a plant leaf.  What process must have taken place?

We hope photosynthesis puts you in a light mood.

​If starch is lacking in a Geranium leaf, cellular respiration has occurred. OR

No photosynthesis has occurred. OR

The plant was kept in the dark.

2. If, in another case, starch is lacking in a leaf, what conclusion can be made?

In red pen, you can add more to your answer.

​The square leaf was in the light because it had starch in it. OR

The square leaf did photosynthesis to make glucose and then starch which showed up as a dark color when the iodine was added.

4. Which plant shape was in the light? Explain clearly. The word starch must be used in your answer.

Please proofread your answers.​

​The triangle shape was in the dark. The triangle has no starch in it because the starch was used up by the plant to survive while in the dark.

OR

The triangle shape tested negative for starch so it had been in the dark (not photosynthesizing).

5. Which plant shape was in the dark? Explain clearly. The word starch must be used in your answer.

Herbivores taste good.

If the absence of light has an effect on the amount of starch in a leaf,

then the leaf that was in the dark for ten days should show a negative test for starch,

because the plant kept in the dark should have used up all of its stored starch by doing cellular respiration.

6. The lab data supported this hypothesis.​

We hope negative tests don't get you down.

If the starch here is made of 20 glucose, then 3 starch is 60 glucose which is more than 44 glucose.

7. Some of the light energy from the sun is stored in the chemical bonds of glucose. Many glucose molecules may be linked together into starch and stored by a plant as starch. In terms of chemical bonds, explain why a starch molecule will have more energy than a glucose molecule.

See the next page for the answer​

A starch molecule is a bunch of glucose molecules chemically bonded together,

so there are more bonds

which will have more energy.