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प्रश्न
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.
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उत्तर
(i) (d) 3.5
(ii) (b) Oxygen
(iii) (c) Water
(iv) (c) Decrease because the temperature drops.
(v) (b) Increases because more photosynthesis occurs.
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संबंधित प्रश्न
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
Mention one difference between the following on the basis of what is given in bracket.
Chlorophyll and chloroplast (part of plant cell)
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:
- What is the objective of this experiment?
- Will it work satisfactorily? Give reason.
- What alteration(s) will you make in it for obtaining expected result?
- Would you take any steps before starting the experiment? Describe this step and explain its necessity.
Chlorophyll is necessary for photosynthesis.
Choose the correct answer:
Chlorophyll is present
Match the terms given in column A with column B:
| Column A | Column B | ||
| (a) | Chlorophyll | (i) | Removes/absorbs CO2 |
| (b) | Methylated spirit | (ii) | Tests presence of starch |
| (c) | Potassium hydroxide | (iii) | Traps solar energy |
| (d) | Iodine solution | (iv) | Produces oxygen |
| (e) | Water | (v) | Bleaches chlorophyll |
Given below is the figure of an experimental set-up, showing a physiological act of the plants. Study and answer the following questions:
- What is the objective of this experiment?
- Name and define the process shown here.
- Why do we destarch the leaves before performing the experiment?
- How do we destarch the leaves?
- What will be the observation when we pour iodine solution over the bleached experimental leaf?
- Write a well-balanced equation for the above process.
Give reasons/explain:
During the starch test, the leaf is boiled in methylated spirit.
