- Take two healthy potted plants which are nearly the same size.
- Keep them in a, dark room for three days.
- Now place each plant on separate glass plates. Place a watch-glass containing potassium hydroxide by the side of one of the plants. The potassium hydroxide is used to carbon dioxide.
- Cover both plants with separate bell-jars as shown in Fig. 6.4.
- Use vaseline to seal the bottom of the jars to the glass plates so that the set-up is air-tight.
- Keep the plants in sunlight for about two hours
- Pluck a leaf from each plant ahd check for the presence-of starch as in the above activty,
- Do both the leaves show the presence of the same amount of starch?
- What can you conclude from this activity?
Dear student,
The leaf from setup (a) will not show the change in color when we put the iodine solution on it as no photosynthesis occurs in setup a because it does not have carbon dioxide, so, no starch will be stored in them. Hence, it will not turn into blue-black color when iodine solution is put on it. This will be because all the carbon dioxide will be absorbed by the potassium hydroxide in the jar and the plant will be unable to perform photosynthesis.
The leaf from setup (b) will show the change in the color because it perform photosynthesis and thus starch will be present in them and it will change into blue-black color in presence of the iodine.
Regards
The leaf from setup (a) will not show the change in color when we put the iodine solution on it as no photosynthesis occurs in setup a because it does not have carbon dioxide, so, no starch will be stored in them. Hence, it will not turn into blue-black color when iodine solution is put on it. This will be because all the carbon dioxide will be absorbed by the potassium hydroxide in the jar and the plant will be unable to perform photosynthesis.
The leaf from setup (b) will show the change in the color because it perform photosynthesis and thus starch will be present in them and it will change into blue-black color in presence of the iodine.
Regards