Advertisements
Advertisements
Question
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?

Advertisements
Solution
(i) To absorb the moisture formed by transpiration.
(ii) Yes, the weight of CaCl2 vials kept on the lower side will be more because transpiration will be more on the lower surface and the moisture absorbed.
(iii) To check the outside and inside pressure.
(iv) Transpiration is the loss of water from the aerial parts of the plant in the form of water vapour.
APPEARS IN
RELATED QUESTIONS
Name the following:
An instrument used to find the rate of transpiration.
Name the following:
The apparatus to record the rate of transpiration in a cut shoot.
What is a photometer?
Droplets of water may sometimes be seen along the margins of the leaves of a banana plant, growing in wet soil, in the mornings. Are these dew drops? Comment upon your answer.
Given below is the diagram of an apparatus used to study a particular phenomenon in plants:

What is the use of the reservoir?
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.
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 |
Define the following term:
Potometer
