(a) What chemical substances are needed for photosynthesis to take place?
(b) Define photosynthesis.
(c) How can the starch test show that food has been prepared in the leaf?

Q. (a) Define 'Photosynthesis'. Apart from sunlight, what other conditions are necessary for the process of photosynthesis.
(b) Describe an experiment to show that "sunlight is essential for photosynthesis".

Q. In the experiment to show that sunlight is necessary for photosynthesis:
(a) What is done to destarch the green leaves of the potted plant initially?
(b) What is done to a part of destarched leaf so that photosynthesis may not take place in that part of the leaf (before keeping the potted plant in sunlight)?
(c) How is chlorophyll removed from the green leaf before further testing?
(d) Which reagent is used to test the presence/absence of starch in the parts of experimental leaf?

Q. If a leaf has undergone photosynthesis, what would be the result of the starch test on this leaf?

Q. On completion of the experiment to demonstrate that ‘Light is necessary for photosynthesis’, four students reported the inference as follows. Identify the correct inference:
(1) Part of the leaf covered with strip can only undergo photosynthesis.
(2) Uncovered part of the leaf cannot synthesise starch
(3) Photosynthesis takes place only in the presence of sunlight
(4) Light is necessary for the synthesis of starch in green plants.