Advertisements
Advertisements
Question
The figure given below is for performing an experiment on photosynthesis.

Answer the following:
(i) What is the aim of this experiment?
(ii) Describe an experiment to show that light is necessary for photosynthesis.
(iii) What do you conclude from this experiment?
(iv) What is the role of light in photosynthesis?
Advertisements
Solution
- To demonstrate that sunlight is necessary for photosynthesis.
- Take a potted plant and keep it for 2-3 days in dark to destarch its leaves. Take one leaf and cover it on both sides with two black paper strips, as shown in the diagram, with the help of cellophane tape. Now keep the potted plant in light. After a few hours pluck the leaf and remove the black strips. Boil the leaf in alcohol and wash it in water. Test the leaf for starch with iodine solution. The leaf turns blue all over except the region covered with black stripes. This shows that the region which did not receive light could not synthesise starch. Thus, light is necessary for photosynthesis.
- Light is necessary for photosynthesis.
- Light supplies energy in the form of photons to split water during tight reaction.
APPEARS IN
RELATED QUESTIONS
The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both testtubes are kept in sunlight. Answer the questions that follow:

(i) Name the physiological process that releases the bubbles of oxygen.
(ii) Explain the physiological process as mentioned above in Q2 (a)(i).
(iii) What is the purpose of keeping a snail in test-tube ‘B’?
(iv) Why does test-tube ‘B’ have more bubbles of oxygen?
(v) Given an example of a water plant that can be used in the above process.
(vi) Write the overall chemical equation for the above process.
Name the following:
The products that are formed as a result of photosynthesis.
The diagram alongside represents an experiment conducted to prove the importance of a factor in photosynthesis.

Study the same and then answer the questions that follow:
(i) Name the factor being studied in his experiment.
(ii) Why was the plant kept in a dark room before conducting the experiment?
(iii}Why was the experimental leaf then kept in
1. boiling water 2. methylated spirit?
(iv) Name the solution used to test for the presence of starch in the leaf.
(v) What will we observe in the experimental leaf at the end of the starch test?
(vi) Give a balanced chemical equation to represent the process of photosynthesis.
Photosynthesis is considered as a process supporting all life on earth.
Explain the Term ATP.
Explain the term Photosynthetic Membrane.
Choose the Odd One Out
Choose the correct option.
For fixation of 6 molecules of CO2 and formation of one molecule of glucose in Calvin cycle, requires
Name the plant part
- Which bends in the direction of gravity but away from the light.
- Which bends towards light but away from the force of gravity.
Where does the carbon that is used in photosynthesis come from?
