Advertisements
Advertisements
Question
What is lenticular transpiration? Mention one major difference between lenticular transpiration and stomatal transpiration.
Advertisements
Solution
Transpiration occurring through lenticels i.e. minute openings on the surface of old stems is called lenticular transpiration.
Stomatal transpiration is controlled by the plant by altering the size of the stoma, where as this does not happen in case of lenticular transpiration. This is because the lenticels never close, but remain open all the time.
The amount of stomatal transpiration is much more than the amount of lenticular transpiration.
RELATED QUESTIONS
Name the following:
An instrument used to find the rate of transpiration.
The apparatus shown here is Ganong's photometer designed to demonstrate unequal transpiration from the two surfaces of a dorsiventral leaf. Before keeping the leaf in between the cups, anhydrous calcium chloride (CaCl2) contained in two small vials were weighted and placed in both the cups. The ends of the cups were weighted and with corks through which two mercury manometers were connected. After a few hours, CaCl2 vials were taken out and weighed again.
(i) What is the purpose of keeping CaCl2 vials inside the cup?
(ii) After a few hours, CaCl2 vials were taken out and weighed again.
will you except any difference in weight? If so, give reasons.
(iii) What was expect the purpose of using a manometer?
(iv) What do you mean by transpiration?

Given below is the diagram of an apparatus used to study a particular phenomenon in plants:

- Name the apparatus.
- What is it used for?
- What is the role played by the air-bubble in this experiment?
- What is the use of the reservoir?
- What happens to the movement of the air-bubble if the apparatus is kept:
- in the dark
- in sunlight
- in front of a fan?
Give a reason in each case.
Given below is the diagram of an apparatus used to study a particular phenomenon in plants:

What is it used for?
The apparatus shown in the following diagram is Garreau’s potometer designed to demonstrate unequal transpiration from the two surfaces of a dorsiventral leaf Before keeping the leaf in between the cups, anhydrous calcium chloride (CaCl2) contained in two small vials were weighed and placed in both the cups. The ends of the cups were closed with corks through which two mercury manometers were connected. After few hours, CaCl2 vials were taken out and weighed again.

What is the purpose of keeping CaCl2 vials inside the cup?
The apparatus shown in the following diagram is Garreau’s potometer designed to demonstrate unequal transpiration from the two surfaces of a dorsiventral leaf. Before keeping the leaf in between the cups, anhydrous calcium chloride (CaCl2) contained in two small vials were weighed and placed in both the cups. The ends of the cups were closed with corks through which two mercury manometers were connected. After few hours, CaCl2 vials were taken out and weighed again.

After few hours CaCl2 vials were taken out and weighed again. Will you expect any difference in weight? If so, give reason.
Write any two limitations of using a Ganong's potometer to demonstrate the uptake of water.
Match the terms given in column A with column B:
| Column A | Column B | ||
| (a) | Hydathodes | (i) | Photosynthesis |
| (b) | Stomata | (ii) | Respiration |
| (c) | Cuticle | (iii) | Regulates opening and closing of stomata |
| (d) | Lenticels | (iv) | Reduces loss of water |
| (e) | Guard cells | (v) | Guttation |
Name four kinds of potometers on the basis of the names of the scientists who discovered them.
Define the following term:
Potometer
