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Question
Given alongside is the diagram of an experimental set-up:
- What is the objective of this experiment?
- Will it work satisfactorily? Give reason.
- What alteration(s) will you make in it for obtaining expected result?
- Would you take any steps before starting the experiment? Describe this step and explain its necessity.
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Solution
- To demonstrate the importance of carbon dioxide in photosynthesis.
- No, the experiment will not work satisfactorily, as the beaker contains lime water and not potassium hydroxide to absorb CO2.
- Place potassium hydroxide in the beaker instead of lime water.
- The plant must be kept in complete darkness for 48 hours in order to destarch its foliage prior to commencing the experiment. The reason for this is that the experiment will yield false results if the plant is not destarched, as the leaf deposited in the beaker may contain starch that was previously stored, even if no starch is produced during the experiment.
RELATED QUESTIONS
Two healthy green plants were placed in the dark for 24 hours. They were then set up, as shown in the figure, for 4 hours. Then a leaf was taken from each plant and
the chlorophyll was removed from the leaves:
( i) What is the next and final step in this experiment?
( ii ) What would be the results of the final step?
( iii ) Why was it necessary to grease the glass sheet?
( iv ) What hypothesis is being tested in this experiment?
Name the following:
The main mineral constituent of chlorophyll.
Name the following:
The source of carbon dioxide for aquatic plants.
Mention one difference between the following on the basis of what is given in bracket.
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Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.
Name the biological process which was the starting point of the whole chain.
A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
During the starch test, why was the leaf
(1) boiled in water
(2) boiled in methylated spirit
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 test-tubes are kept in sunlight. Answer the questions that follow:
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(b) Explain the physiological process as mentioned above in (a).
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(e) Give an example of a water plant that can be used in the above experiment.
(f) Write the overall chemical equation for the above process.
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Which of the following is used to remove chlorophyll from the leaves?
Given below is the figure of an experimental set-up, showing a physiological act of the plants. Study and answer the following questions:
- What is the objective of this experiment?
- Name and define the process shown here.
- Why do we destarch the leaves before performing the experiment?
- How do we destarch the leaves?
- What will be the observation when we pour iodine solution over the bleached experimental leaf?
- Write a well-balanced equation for the above process.
