Advertisements
Advertisements
प्रश्न
A potted destarched plant was taken in order to prove that light is necessary for photosynthesis.
(i) What is meant by 'destarched plant'? How can it be destarched?
(ii) Using the destarched plant describe step by step how you would proceed to prove that in the absence of light the leaf cannot manufacture starch.
उत्तर
(i) Destarched plant is the plant which lacks starch. Destarching is done by keeping the plant in dark for 2-3 days or covering a part of a leaf with a black paper by clip.
(ii) (a) The leaf is plucked and is boiled in water and decolourized with alcohol.
(b) The portion of leaf which received light turns blue with iodine because photosynthesis took place in that part of leaf.
(c) The part of leaf which was covered with black paper remains colourless because photosynthesis could not take place in the absence of sunlight.
This shows that starch is not manufactured in the absence of light.
APPEARS IN
संबंधित प्रश्न
The solvent used to dissolve the chlorophyll pigments while testing a leaf for starch is Soda lime.
ATP [Expand the abbreviation]
(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 ______.
Enumerate the steps involved in testing a green leaf for the presence of starch.
What is meant by a destarched plant? How can it be destarched?
Using the destarched plant describe step by step how would you proceed to prove that in the absence of light the leaf cannot manufacture starch?
A candidate in order to study the importance of certain factors in photosynthesis took a potted plant and kept it in the dark for over 24 hours. Then in the early hours of the morning, she covered one of the leaves with black paper in the center only. She placed the potted plant in the sunlight for a few hours, and then tested the leaf which was covered with black paper for starch.
- What aspect of photosynthesis was being investigated?
- Is there any control in this experiment? If so, state the same.
- Why was the plant kept in the dark before the experiment?
- Describe step by step how the candidate proceeded to test the leaf for the presence of starch.
Name two raw materials for photosynthesis.
Write the exact location of palisade cells.
