Question

what is the process of transpiration experiment
In the form of
1.aim
2.apparatus
3.precautions
4.procedure
5.observation
6.inference

Answer 1

Experiment # 1. Measurement of Leaf Area:

The loss of water in the form of vapour from the aerial parts — particularly through leaves — is termed “transpiration”. On absorption from the soil by roots, the water is trans-located via the xylem tissue to the mesophyll cells of the leaves.

The excess water is lost through stomatal opening or through the diffusion process from leaf surface. For determination of the rate of transpiration, measurement of leaf area, i.e. transpiring surface, is highly essential. The leaf area can be measured by different methods.Method I: By Graph Paper Method:

ADVERTISEMENTS:

Requirements:

1. Graph paper (mm); 2. Scale, pencil, leaf, etc.

Procedure:

1. Place leaf on a millimeter graph paper and draw its outline with a pencil (Fig. 3.11).



2. Then count the total area covered by the leaf from the marked outline of the leaf and express it as square centimeter.

Observation:

The leaf area measurement procedure is shown in Fig. Method III: By Planimeter Method:

Requirements:

1. Planimeter — a simple instrument, having two major parts — a tracer arm having a tracing point and a carriage with a measuring wheel and also the pole arm attached to the pole, around which the instrument revolves (Fig. 3.13).



2. A platform, leaf, pencil etc.

Procedure:

1. Place the leaf on a platform in a fixed position and draw the outline of the leaf by a pencil.

2. Place the pole weight close to the outline of the leaf and move the tracer point along the margin of the leaf.

3. Record the initial reading from the scale and final reading after the tracing of leaf.

4. Compute the total leaf area by denoting the data from the main scale and also from vernier scale.

5. Record the vernier scale reading in the following ways before final computation:

First coincide the zero of the measuring wheel with zero of the vernier scale. Find out the number of divisions of the vernier scale that coincides with that of the measuring wheel.

Suppose 10 vernier divisions = 9 divisions of measuring wheel. So, 1 vernier division = 9/10 or 0.9 division of the measuring wheel. Vernier unit = 1 – 0.9 = 0.1 sq. cm small division of the measuring wheel = 1 sq. cm and 1 div. of the counter dial = 100 sq. cm.

Thus total reading = (Counter dial reading × 100) + (Measuring wheel reading × 10) + (vernier reading × 0.10) sq. cm.

Answer 2

The loss of water as water vapour from the Arial surface of the leaves is known as transpiration. The water is heated by the sun converts into vapor and then evaporate, and passes out through thousands of tiny pores called the stomata mostly on the underside of the leaf surface. This is the process of transpiration. It has two primary functions: cooling the plant and pumping water and minerals to the leaves for photosynthesis by ascend of sap.