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प्रश्न
Photosynthesis in green plants is directly and indirectly dependent on so many plant structures.
Explain briefly the role of the following structures in this process Guard cells.
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उत्तर
Guard cells: They regulate the opening and closing of stomata and thus regulate the entry of carbon dioxide through the stomata.
संबंधित प्रश्न
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?
The diagram is set up to demonstrate an experiment. Pond weed was placed in five water-filled tubes. The experiment was set up as shown in the diagram. The tubes were then left for 24 hours. Write the correct answer out of the five available choices:
(i) In which tube would you except to find the plant with the least amount of starch?
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(ii) The tube in which most oxygen would be found is
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(iii) The tube in which least carbon dioxide would be found is
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(iv) The tube in which the plant would survive for the shortest length of time is
(a ) 1 (b) 2 (c) 3 (d) 4 (e) 5
All life owes its existence to chlorophyll. Give reason.
Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.
- Name the phenomenon represented.
- Name any one organism that could be shown at No. 5.
- Name the biological process which was the starting point of the whole chain.
- Name one natural element which all the organisms 2-4 and even 5 are getting from No. 1 for their survival.
Given alongside is the diagram of an experimental set-up:
Will it work satisfactorily? Given reason.
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.
Why was the plant placed in the dark before beginning the experiment?
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
Chlorophyll is necessary for photosynthesis.
Give reasons/explain:
During the starch test, the leaf is boiled in methylated spirit.
