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Question
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.
Options
True
False
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Solution
This statement is false.
Explanation:
Destarching of the foliage of a potted plant can occur not only at night but also when the plant is exposed to continuous darkness for a specific period. This process can be occur in the absence of light and entails the removal of stored starch.
RELATED QUESTIONS
An experiment was set up as shown in the figure given below . The twig in the diagram was intact on the plant and it was as such in sunlight for a few hours .
(i) What is the aim of the above experiment ?
(ii) Why was potassium hydroxide placed inside the conical flask ?
(iii) What test would you perform on the leaf inside the flask?
(iv) What is the expected result of the above test ?
(v) Is it necessary to similarly test on outer leaf also ? Giva a reason .
Fill in the blank:
Land plants obtain their carbon dioxide from the ______.
The diagram alongside refers to an experiment in which the apparatus was set up with the light source 10 cm away from the plant. After 15 minutes the number of bubbles evolved per minute from the cut stem was recorded. The light source was moved to 20 cm away from the plant, left for 15 minutes and the number of bubbles evolved per minute was again recorded. The experiment was repeated with the light source at distances of 40, 60, 80 and 100 cm away from the plant. Plot a graph for the results obtained and answer the following questions.
(i) From the graph it seems likely that the rate of bubbling per minute at 50 cm would have been
(a) 2.0 (b) 2.5 (c) 3.0 (d) 3.5
(ii) The gas produced by the plant during the experiment was
(a) air (b) oxygen (c) carbon dioxide (d) nitrogen (e) hydrogen
(iii) The gas collected comes due to the breakdown of
(a) glucose (b) starch (c) water (d) air (e) ATP
(iv) If ice cubes were added to the water, the rate of bubble formation would
(a) Stay the same.
(b) Increase because more water is added.
(c) Decrease because the temperature drops.
(d) Decrease because water freezes.
(e) Cannot tell from the information given.
(v) If some sodium bicarbonate is added to the water the rate of bubble formation
(a) Increases because more respiration occurs.
(b) Increases because more photosynthesis occurs.
(c) Increases because the gas becomes less soluble.
(d) Decreases because carbon dioxide acts as a limiting factor.
(e) Decreases because respiration decreases.
The chemical substance used to test the presence of starch in the cell of a leaf is ______.
Why is it not possible to demonstrate respiration in a green plant kept in sunlight?
How do non-green plants such as fungi and bacteria obtain their nourishment?
Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.
Name the biological process which was the starting point of the whole chain.
Complete the following sentence with appropriate word:
________molecules of chlorophyll make one quantasome.
Choose the correct answer:
Chlorophyll is present
Give reasons/explain:
During the starch test, the leaf is boiled in water.
