An onion peel was taken and
(a) placed in salt solution for five minutes.
(b) after that it was placed in distilled water.
When seen under the microscope what would be observed in (a) and (b)?
(a) Onion peel when placed in salt solution, shrinks as water from cells cytoplasm moves out of the cell i.e., hypertonic solution.
(b) When it is placed again back in distilled water, cell regains it's shape and absorbs water and become turgid (full of water) i.e., hypertonic solution.
Difference between apoplast pathway and symplast pathway is as follows
| Apoplast Pathway | Symplast Pathway |
|---|---|
| It consists of the non-living parts of plant body, i.e., cell walls and inter cellular spaces. There is a little resistance in the movement of water in apoplastic pathway. It is a faster process. |
It consist of living parts of plant body, i.e., protoplast connceted by the plasmodesmata. Some resistance occurs in the movement of water through symplast. It is a slightly slower process. |
Casparian strip is found in the endodermis. The walls of this layer are impervious to water because of the presence of suberin. So, it does not allow movement of water across the endodermis, rather is forced to enter the symplast pathway through cell membranes and reaches the xylem.
Difference between guttation and transpiration is as follows
| Guttation | Transpiration |
|---|---|
| Guttation is the loss of liquid droplets from the plants. | It is the loss of water by a plant in the form of vapours. |
| Guttated water is a dilute solution of both inorganic and organic substances. | Transpired water is a pure water. |
| Guttation occurs at the margins and the tips of the leaves. | Transpiration occurs through the general surface of the leaves and the young stem. |
| Excessive guttation does not cause loss of turgidity. | Excessive transpiration results in wilting in severe cases, could be lethal to plant. |