Advertisements
Advertisements
Questions
Why is it not possible to demonstrate respiration in a green plant kept in sunlight?
Give reasons/explain:
It is not possible to demonstrate respiration in a green plant kept in sunlight.
Solution 1
If a green plant is kept in bright light, it tends to use up all the CO2 produced during respiration for photosynthesis. Thus, the release of CO2 cannot be demonstrated. Hence, it is difficult to demonstrate respiration as these two processes occur simultaneously.
Solution 2
When a plant is kept in sunlight, CO2 released by respiration gets used by photosynthesis to synthesise food. So no carbon dioxide is liberated, and respiration cannot be demonstrated.
RELATED QUESTIONS
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
Are the following statement true or false? Give a reason in support of your answer.
Destarching of the leaves of a potted plant can occur only at night.
How would you demonstrate that green plants release oxygen when exposed to light?
Complete the following by filling the blanks 1 to 5 with appropriate words/terms/phrases:
To test the leaf for starch, the leaf is boiled in water to ______ (1). It is next boiled in methylated spirit to ______ (2). The leaf is placed in warm water to soften it. It is then placed in a dish and ______ (3) solution is added. The region which contains starch, turns ______ (4) and the region which does not contain starch, turns ______ (5)
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
The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both test-tubes are kept in sunlight. Answer the questions that follow:
(a) Name the physiological process that releases the bubbles of oxygen.
(b) Explain the physiological process as mentioned above in (a).
(c) What is the purpose of keeping a snail in test-tube B?
(d) Why does test-tube B have more bubbles of oxygen?
(e) Give an example of a water plant that can be used in the above experiment.
(f) Write the overall chemical equation for the above process.
Where are the chlorophyll pigments present in a cell?
Name the following:
Light in which the maximum rate of photosynthesis takes place.
Complete the following sentence with appropriate word:
________molecules of chlorophyll make one quantasome.
