Photosynthesis, Plant converts solar energy into chemical energy.

 To demonstrate that the light is necessary for photosynthesis.


AIM  :  To demonstrate that the light is necessary for photosynthesis.


PRINCIPLE :  During the process of photosynthesis plant converts solar energy into chemical energy ( glucose ). This experiment indicates that without light, food cannot be synthesized.

MATERIALS :  Ganong’s screen, a twig, iodine, ventilated box,  etc.

Plant with leaf

Photosynthesis, light is necessary.

Cobalt Chloride paper on leaf.

Sun light makes Photosynthesis process.

Result (Observation) :

The positive iodine test shows presence of starch only is the region where letter “A” was cut in the black paper.

Conclusion :

The final product of the photosynthesis is starch. It is found in the leaf only when all the essential factors for the photosynthesis are available to the plant. The iodine test shown that starch is manufactured in the region exposed to the light, while the region of the leaf which was covered with black paper does not show any starch.

Application :

From this experiment we can demonstrate to the students that for the synthesis of starch, light is necessary.