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प्रश्न
Describe briefly the three physical properties of water which helps in ascent of water in xylem.
उत्तर
Following are the three physical properties of water that help in the ascent of water in the xylem.
- Cohesion: It is the ability of water molecules to stick to each other.
- Adhesion: It is the ability of water molecules to stick to a surface.
- Surface Tension: The property of any liquid that tends to occupy the smallest possible surface area is called surface tension. Water makes a continuous column of water in the xylem vessels by adhesion cohesion and surface tension. Transpiration pull pulls this water as a column.
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संबंधित प्रश्न
An apparatus, as shown below, was set up to investigate a physiological process in plants. The setup was kept in sunlight for two hours. Droplets of water were then seen inside the bell jar. Answer the questions that follow:
- Name the process being studied.
- Explain the process named above in Q.3(a)(i).
- Why was the pot covered with a plastic sheet?
- Suggest a suitable control for this experiment.
- Mention two ways in which this process is beneficial to plants.
- List three adaptations in plants to reduce the above mentioned process.
Give a reason.
What happens to the movement of the air-bubble if the apparatus shown above is kept in front of a fan?
Give a reason.
What happens to the movement of the air-bubble if the apparatus shown above is kept in dark.
A well watered healthy potted plant with variegated leaves was kept in darkness for about 24 hours. It was then set up as shown in the diagram and exposed to light for about 12 hours. At the end of this time, leaf x and y were tested for starch. Study the diagram and answer the questions that follow:
(i) Why was the plant initially kept in darkness for 24 hours?
(ii) What is the function of sodium hydroxide solution in the flask?
(iii) Select the correct leaf from the five available choices shown in the diagram as a, b, c, d and e. Rewrite the correct answer by filling in the appropriate letter for the questions that follow:
1. After the starch test, leaf x would look like ______.
2. After the starch test, leaf y would look like ______.
(iv) The experiment with leaf y shows that photosynthesis requires the presence of certain factors. Mention any one factor.
What are stomata? What governs the opening and closing of stomata?
Answer the following question.
Define and or explain the term:
Transpiration
Transpiration takes place through ______.
How can plants be grown under limited water supply without compromising on metabolic activities?
A root hair is derived from ______ cell.
Which of the following is an external factor affecting the rate of transpiration?
