Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
- In a dark room, a leaf on the destarched plant is covered on either side with strips of black paper which are kept in place by paper clips or cellophane tape.
- Now the potted plant is kept in the light.
- After a few hours, the leaf is detached from the plant and the black strips are removed.
- Then the leaf is boiled in water for 2-3 minutes and then boiled in alcohol to remove the green chlorophyll.
- The leaf is then washed in water and tested with iodine.
- The region of the leaf that was under the black strip turns yellowish-brown showing that no starch was made, while the rest of the leaf turns bluish-black showing the starch was made in the presence of light.
APPEARS IN
संबंधित प्रश्न
Phosphate, RNA, Sugar, Nitrogenous base
Put a tick (✓ ) against the most appropriate alternative in the following statement.
Stomata are present on the surface of:
Given below is the overall chemical equation of photosynthesis which is incomplete in certain respects.
\[\ce{CO2 + H2O ->[Chlorophyll] C6H12O6 + H2O + O2} \]
Rewrite the equation in its complete form .
A leaf is a food factory. Explain.
On a bright sunny day, water weeds growing in an aquarium were actively giving off bubbles of gas. Use this information to answer questions that follow:
- Name the process occurring in the water weed that has resulted in the evolution of these bubbles.
- Of what gas do these bubbles consist?
- Briefly describe the reactions occurring in the leaves of the water weeds leading to the evolution of these bubbles.
- Give an overall balanced chemical equation to represent the process named in (i) above.
What is meant by a destarched plant? How can it be destarched?
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.
State whether true or false. If false, correct the statement.
Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
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 ______.
