The water potential of pure water is

(1) zero

(2) less than zero

(3) more than zero, but less than one

(4) more than one

Which of the following facilitates opening of stomatal aperture :-

(1) Contraction of outer wall of guard cells

(2) Decrease in turgidity of guard cells

(3) Radial orientation of cellulose microfibrils in the cell wall of guard cells

(4) Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells

Which of the following facilitates opening of stomatal aperture?

1. Decrease in turgidity of guard cells

2. Radial orientation of cellulose microfibrils in the cell wall of guard cells

3. Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells

4. Contraction of outer wall of guard cells

The water potential of pure water is:

1. Less than zero

2. More than zero but less than one

3. More than one

4. Zero

A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap?

(1) Acidic

(2) Alkaline

(3) Low refractive index

(4) The absence of sugar