Question

The diagram of an apparatus given below demonstrates a particular process in plants. Study the same and answer the questions that follow

1. Name the apparatus.
2. Which phenomenon is demonstrated by this apparatus?
3. Explain the phenomenon mentioned in 2. above.
4. State two limitations of using this apparatus.
5. What is the importance of the air bubble in this experiment?
6. Name the structure in a plant through which the above processes take place.

Answer 1

1. Apparatus:

• The apparatus given is Ganong's Potometer.

2. Phenomenon demonstrated:

• The phenomenon demonstrated by the apparatus is transpiration.

3. Explanation of the phenomenon:

• Transpiration is the process in which water is lost in form of vapor from the aerial parts of the plant.
• Roots absorb water from the soil and reach the aerial parts of the plants through a xylem vessel.
• Excess water from the plant is diffused out in the form of vapor from the surface of the leaves.

4. Limitations:

• The process of introducing the air bubble is not easy.
• The twig might not remain alive for a long time.

5. Importance of air bubble:

• The air bubble helps in measuring the rate of transpiration.

6. Structure from where transcription occurs:

• Transpiration occurs from the aerial parts of the plant like stomata, lenticels, and cuticles.