Limitations of Ganong's Potometer.

Q. (a) What is the apparatus shown below called? State its purpose.

(b) State the use of:
(i) Capillary tube
(ii) Scale
(iii) Water reservoir

(c) What happens to the movement of air bubbles if the apparatus is kept:
(i) in sunlight;
(ii) in darkness;
(iii) in front of a fan? [5 MARKS]

Q.

What measures should be taken to obtain accurate readings in a potometer?

1. The potometer should be completely airtight.

2. The twig should be cut obliquely - to allow a larger surface area for more intake of water.

3. Place the twig underwater - to avoid the suction of air bubble into the xylem which might hinder absorption.

4. The potometer should allow air inside the apparatus.

Q.

Which of the following are considered to be limitations while using a potometer?

1. Introducing the air bubble into the capillary tube is not easy

2. The twig may not remain alive for a long time

3. Any changes in the outside air temperature may affect the position of the air bubble in the capillary tube

4. All of the above

Q.

Why do we only use a small twig in the potometer setup ?

Q. Here is the diagram of an apparatus used to study a particular phenomenon in plants:
Name the apparatus.

Q. Identify the following instrument used to measure rate of transpiration.


Hint: Unscramble TPMEOTROE

Q.

Mention any one limitation of using potometer.