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प्रश्न
Enumerate the steps involved in testing a green leaf for the presence of starch.
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उत्तर
Test to determine the presence of starch in a leaf:
- Dip a leaf in boiling water for a minute to kill the cells.
- Boil the leaf in methylated spirit in a water bath to remove the chlorophyll, till the leaf turns pale blue and becomes hard and brittle.
- Now place the leaf in hot water to soften it.
- Place the leaf in a Petri dish and pour iodine solution over it.
- The appearance of a blue-black colour on the leaf is indicative of the presence of starch.
- The absence of starch is indicated by a brown colouration.
संबंधित प्रश्न
The solvent used to dissolve the chlorophyll pigments while testing a leaf for starch is Soda lime.
(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.
(iv) Which one of these two reactions is the supporter of all life on earth?
In the flowering plants, food is transported in the form of ______.
What is meant by a destarched plant? How can it be destarched?
Name the following:
The chemical substance used to test the presence of starch in the cell of a leaf.
State whether true or false. If false, correct the statement.
Photosynthesis produces glucose and carbon dioxide.
State whether true or false. If false, correct the statement.
Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
Write the reaction for photosynthesis?
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.
______ food is made in their green stems.
