water goes in by osmosis and nothing is mentioned regarding diffusion. Someone, please clarify this.
You'll need a good understanding of the difference between osmosis and diffusion for this.
Osmosis is a special kind of diffusion.
The only difference between the two is the molecules that are carried. Diffusion is used to transport solute molecules, whereas osmosis is used to transport solvent molecules (in most cases water). In both situations, until equilibrium is reached, the movement is from a higher concentration gradient to a lower concentration gradient.
Regarding the movement of water through the various pathways.
I'm quoting this directly from the Plant Physiology book (Taiz and Zeigner). Please refer to the same for more information.
In the soil, water is transported predominantly by bulk flow.
However, when water comes in contact with the root surface,
the nature of water transport becomes more complex.
From the epidermis to the endodermis of the root, there are
three pathways through which water can flow:
the apoplast, transmembrane, and symplast pathways.
In the apoplast pathway, water moves exclusively
through the cell wall without crossing any membranes.
The apoplast is the continuous system of cell
walls and intercellular air spaces in plant tissues.
The transmembrane pathway is the route followed
by water that sequentially enters a cell on one side,
exits the cell on the other side, enters the next in the
series, and so on. In this pathway, water crosses at
least two membranes for each cell in its path (the
plasma membrane on entering and on exiting).
Transport across the tonoplast may also be involved.
In the symplast pathway, water travels from one cell
to the next via the plasmodesmata. The symplast consists of the entire network of cell cytoplasm interconnected by plasmodesmata.
Please follow the three pathways in the image to get the insights.
