Question

Correct the statements
a. Cells shrink in hypotonic solutions and swell in hypertonic solutions.
b. Imbibition is a special type of diffusion when water is absorbed by living cells.
c. Most of the water flow in the roots occurs via the symplast.

Answer 1

Hypertonic solution:

Hypertonic solution is a type of solution having lower water potential as compared to the cytoplasm of the cell. When a cell is placed in such a solution, the water moves out of the cell due to the difference in water potential and causes the cell to shrink.


Hypotonic solution:

Hypotonic solution is a solution having higher water potential as compared to the cytoplasm of the cell. When a cell is placed in such a solution, the water moves into the cell due to the difference in water potential and causes the cell to swell.


Final answer: Cell shrinks in hypertonic solutions and swells in hypotonic solutions.


Imbibition:

Imbibition refers to a special kind of diffusion where water is absorbed by the surface of solids and colloids resulting in increasing the volume of the substance.


Significance:

Imbibition is called a type of diffusion because water moves along a concentration gradient; there is no water in the seeds and dry wood so they absorb water easily. The imbibition pressure allows for the germination of the seeds.


Final answer: Imbibition refers to a special kind of diffusion when water is absorbed by living cells or dead cells.


Introduction:


Water and mineral solutes are absorbed by the root hairs by diffusion. After water is absorbed by the root hairs, it goes into root layers by two distinct pathways:

• apoplastic pathway
• symplastic pathway

Apoplastic pathway:

Apoplastic pathway is when the water passes through intercellular spaces and cell walls of the cells. It does not cross the cell membrane or enter the cytoplasm of the cells. This pathway takes place in roots as the cortical cells are loosely packed and there is no resistance to water movement.


Symplastic pathway:

The movement of water through the endodermis is symplastic due to the casparian strip. The casparian strip is made up of suberin and therefore is impermeable to water. The symplastic pathway involves the movement of water through the cytoplasm of the endodermal cells.


Final answer: Most of the water flow in the roots occurs via the apoplast.