Question

What is the relative difference in magnitude between the stomatal resistance and the cuticular resistance for your shoot material? What is responsible for the difference in resistancne? Is the transpiration rate constant throughout an entire 24-h period? Justify your answer.

Answer 1

Stomatal resistance: It is the opposition to transport carbondioxide or water vapours etc. through stomatal pores on plant leaves.

Cuticular resistance is the opposition of exchange or loss of moisture form out waxy layer of leaves and other plant parts.

There are various factors responsible for differences in resistance:

1.      Temperature

2.      Humidity

3.      CO2/O2 content

4.      Sunlight

5.      Water-intake by plant

6.      Transpiration rate etc.

Transpiration rate is not constant though-out the day. It changes from morning to evening depending upon sensitivity of sunlight, temperature, humidity and water intake by plant etc.