Water Transport in Plants

Questions and Answers

What is the pathway through which water moves from one cell to another with less resistance, and what is the reason for this?

The pathway is the non-living pathway, and the reason is the adhesion of water molecules to the cell wall due to its hydrophilic nature.

What is the driving force behind the movement of water from the root to the leaves, and in which direction does it move?

The driving force is the hydrostatic pressure, and the direction of movement is down the water potential gradient.

What is the role of plasmodesmata in the movement of water, and how does it occur?

Plasmodesmata allow for the movement of water from one cell to another through diffusion, allowing for the transfer of water molecules between adjacent cells.

What is the process by which water evaporates from the surface of mesophyll cells in the leaves, and what is the result of this process?

The process is transpiration, and the result is a decrease in water potential in the mesophyll cells, leading to more water entering from the xylem vessels. Signup and view all the answers

What is the transpiration pull, and how does it contribute to the movement of water in the plant?

The transpiration pull is the negative pressure created at the top of the xylem vessels, which pulls water up the plant, and it contributes to the mass flow of water through the xylem vessels. Signup and view all the answers

How does water enter the root from the soil, and what is the direction of this movement?

Water enters the root from the soil through root hair cells by osmosis, and the direction of this movement is down the water potential gradient. Signup and view all the answers

What is the result of creating a transpiration pull in xylem vessels?

a transpiration stream, where water with dissolved minerals moves up in the xylem vessels in a continuous water column from root to leaves Signup and view all the answers

What is responsible for maintaining the transpiration stream in xylem vessels?

cohesion between water molecules, adhesion force between water molecules and walls of the xylem vessels, and high hydrostatic pressure Signup and view all the answers

What is the main pathway for water movement across the cortex in the root?

Both apoplast and symplast pathways. Water moves through the cell wall and intercellular spaces (apoplast pathway), and also through the cytoplasm of cells (symplast pathway) Signup and view all the answers

What is the role of the endodermis in the movement of water into the xylem vessels?

The endodermis is the site where water moves from the cortex into the xylem vessels. Signup and view all the answers

What is the driving force behind the movement of water up the xylem vessels?

Transpiration pull, which is a suction force created by the evaporation of water from the leaves Signup and view all the answers

What is the significance of the hydrophilic nature of cellulose and lignin in the xylem vessels?

It creates high hydrostatic pressure due to hydrogen bonds, which helps to maintain the transpiration stream Signup and view all the answers

How does water vapor diffuse out of the leaf?

Through stomata down a water potential gradient Signup and view all the answers

What happens to the hydrostatic pressure in xylem vessels when water is removed from the leaf?

It becomes lower at the top of the xylem vessels, causing a negative pressure Signup and view all the answers

How does water move from the xylem vessels into the mesophyll cells in the leaf?

Through pits in the xylem vessels into the mesophyll cells down a water potential gradient Signup and view all the answers

What are the two pathways by which water can enter the mesophyll cells from the xylem vessels?

Symplast pathway (through cytoplasmic and vacuolar pathways) and apoplast pathway (through cell walls) Signup and view all the answers

How does water move from the roots to the stem to the leaf in xylem vessels?

Through a negative pressure gradient, from high to low hydrostatic pressure Signup and view all the answers

What is the role of stomata in the movement of water out of the leaf?

Allowing water vapor to diffuse out of the leaf down a water potential gradient Signup and view all the answers