Measurement of Transpiration by Indirect Evaporation.

Q.

How to determine whether a leaf is monocot or dicot and how does it affect transpiration?

Q.

The apparatus shown in the given diagram is Garreaus potometer designed to demonstrate unequal transpiration from the two surfaces of a dorsiventral leaf. Before keeping the leaf in between, the cups were closed with corks through which two mercury manometers were connected. After few hours, CaCl2 vials were taken out and weighed again.

(a) What is the purpose of keeping CaCl2 vials inside the cup?
(b) After few hours CaCl2 vials were taken out and weighed again. Will you expect any difference in weight? If so, give reason.
(c) What was the purpose of using a manometer?
(d) What do you mean by transpiration? [5 MARKS]

Q.

Which of the following methods are used to measure transpiration?

1. Weighing method

2. Potometer method

3. Bell jar experiment

4. Cobalt chloride paper

Q.

The apparatus shown in the following diagram is Garreau'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 $CaC{l}_2$ 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, $CaC{l}_2$ vials were taken out and weighed again.

(a) What is the purpose of keeping $CaC{l}_2$ vials inside the cup?

(b) After a few hours, $CaC{l}_2$ vials were taken out and weighed again. Will you expect any difference in weight ? If so, give reason.

(c) What was the purpose of using a manometer?

(d) What do you mean by transpiration?

Q. How would you prove that the lower surface of the leaf transpires more than the upper surface? [4 MARKS]

Q. The given figure represents an experiment performed to demonstrate certain phenomenon in plants. The set-up was kept in sunlight for about two hours. [5 MARKS]

(a) What is the aim of the experiment?
(b) Define the process mentioned in (a) above.
(c) What do you observe in the experiment as an evidence of the process stated in (a) and (b) above?
(d) What precautions are taken for obtaining proper results in the experiment?
(e) Suggest a suitable experiment for comparison.

Q.

There is unequal transpiration from the two surfaces of a dorsiventral leaf.

1. True

2. False

Q. State the function of the following:
Potometer:

[1 Mark]

1. Measures the rate of cell division in plants
2. Measures the rate of photosynthesis in plants
3. Measures the rate of transpiration in plants
4. Measures the rate of respiration in plants

Q.

The figure given below represents an experimental setup with a weighing machine to demonstrate a particular process in plants.

The experimental setup was placed in bright sunlight. Study the diagram and answer the following questions.

1. Name the process intended for study.
2. Define the above-mentioned process.
3. When the weight of the test tube (A and B) is taken before and after the experiment, what is observed? Give reasons to justify your observation in A and B.
4. What is the purpose of keeping the test-tube B in the experimental setup?

Q.

Reduction in the weight of a potted plant after a certain period confirms loss of water through transpiration. Justify.

Q. The figure given below represents an experimental set up with a weighing machine to demonstrate a particular process in plants. The experimental set up was placed in bright sunlight. Study the diagram and answer the following questions :
(i) Name the process intended for study.
(ii) Define the above mentioned process.
(iii) When the weight of the test tube (A & B) is taken before and after the experiment, what is observed ? Give reasons to justify your observation in A &B.
(iv) What is the purpose of keeping the test tube 'B in the experimental set up ?

Q. _________ paper is used to check the presence of moisture in the air.

1. Sodium chloride
2. Litmus
3. Sand
4. Cobalt chloride

Q.

Given below is the diagram of an experimental set-up to study the process of transpiration in plants. Study the same and then answer the question that follows:

Define the term transpiration.

Q.

Cobalt chloride paper is ______ in colour when moist.

1. red

2. green

3. pink

4. purple

Q.

Garreau's potometer

1. helps to measure intake of water by the plant

2. helps to measure loss of water during transpiration

3. demonstrates the suction force created due to transpiration

4. demonstrates the unequal transpiration from the two surfaces of a dorsiventral leaf

Q. Rate of transpiration in a dorsiventral leaf is

1. Greater at the upper surface
2. Greater at the lower surface
3. Equal at both the surface
4. Not related to surfaces

Q.

Which of these would you use to prove that more water vapour is lost from one of the surfaces of a leaf?

1. Cobalt chloride paper

2. Parchment paper

3. Litmus paper

4. Cellophane

Q. Transpiration as percentage of evaporation is called

1. Transpiration index
2. Transpiration ratio
3. Water requirement
4. Transpiration coefficient

Q.

On an extremely hot day, the rate of transpiration would:

1. Be maximum

2. Be lesser than on a cold day

3. Be the same as on an extremely cold day

4. Be almost zero

Q. Write a note on the weighing method to check transpiration.

Q. ___________ is used to indicate the rate of water loss through leaf surface.

1. Litmus Paper
2. Cobalt chloride paper
3. Adhesive tape
4. Sand paper

Q. Instrument that can be used to demonstrate transpirational pull due to vaporization of water is

1. Potometer
2. Auxanometer
3. Atmometer
4. Anemometer

Q.

The figure given below represents an experimental setup with a weighing machine to demonstrate a particular process in plants. The experimental setup was placed in bright sunlight. Study the diagram and answer the following questions:

Name the process intended for study?

Q. Here is the diagram of an experimental set-up to demonstrate a certain phenomenon in plants.
Would it make a difference if the experimental set-up is kept in bright sunshine?

Q.

Which of these would you use to prove that more water vapour is lost from one of the surfaces of a leaf?

1. Cobalt chloride paper

2. Parchment paper

3. Cellophane

4. Litmus paper

Q.

Most of the transpiration in tall trees occurs through which of the following:

• stomata
• lenticels
• cuticle
• bark

Q.

Give biological explanations of the following :

On a bright sunny day, the leaves of certain plants roll up.

Q. The figure given below represents an experimental set up with a weighing machine to demonstrate a particular process in plants. The experimental set up was placed in bright sunlight. Study the diagram and answer the following questions:


(a) Name the process intended for study.

(b) Define the above mentioned process.

(c) When the weight of the test tubes A and B is taken before and after the experiment, what change is observed? Justify.

(d) What is the purpose of keeping the test tube B in the experimental set up?

(e) What is the purpose of putting oil in the test tube?