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Question
A healthy croton plant bearing variegated leaves was kept in a dark cupboard to destarch it after which it was placed in sunlight for a few hours. One of the leaves was then plucked and an outline of the leaf marking the green and the non-green regions was drawn. The leaf was then tested for starch. Using the above information, answer the following questions:
- State the aim of the above experiment.
- Name the chemical used for testing the presence of starch.
- Why is the leaf boiled in water and alcohol before testing for the presence of starch?
- What change is seen on the leaf after the starch test?
- Give the chemical equation to represent the process of starch formation in plants.
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Solution
- Chlorophyll is necessary for photosynthesis.
- Iodine solution.
- the leaf is boiled in water to kill the cells and boiled in alcohol to remove chlorophyll.
- The green parts of the leaf turned blue-black while non-green parts turned brown.
- \[\ce{6CO2 + 12H2O->[Light energy][ChlorophyII]C6H12O6 + 6H2O + 6O2 ^}\]
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RELATED QUESTIONS
The solvent used to dissolve the chlorophyll pigments while testing a leaf for starch is Soda lime.
Phosphate, RNA, Sugar, Nitrogenous base
(i) Fill in the blanks in the following equations of two chemical reactions:
(a) \[\ce{---+12H2O->[Light energy]C6H12O6 + --- + ----}\]
(b) \[\ce{--- 6O2->[Chlorophyll] 6 --- +6 ---- + Energy}\]
(ii) Name the two processes represented by the above two reactions.
(iii) State any two differences in these processes other than those already indicated in the reactions.
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In-plant cells, carbohydrates are stored in which form.
State whether true or false. If false, correct the statement.
Photosynthesis produces glucose and carbon dioxide.
The reactions of photosynthesis make up a biochemical pathway.
Explain how the biochemical pathway of photosynthesis recycles many of its own reactions and identify the recycled reactants.
The raw material which is reduced during photosynthesis is ______.
Name four essentials for photosynthesis.
