movement of water through plants ( xylem )

what does the term plasmodesmata mean ?

Is the gaps in the cell wall containing cytoplasm that connects two cells

what are some specialist features of the root hair cells ?

large SA

lacks chloroplast

many mitochondria

how does mineral ions ( Mg & nitrates ) enter the root hair cells from the soil to x ?

By active transport which requires energy from hydrolysis of ATP to move against the concentration gradient

does the water potential increases or decreases inside the root hair cell ?

the water potential decreases inside the root hair cell → water move from a higher water potential in the soil to the lower water potential in the root hair cell by osmosis.

what are the names of the different pathways of water travelling ?

The apoplast pathway

The symplast pathway

The vacuolar pathway

what is function of the symplast pathway ?

The water absorbed from the soil enters the cell cytoplasm of the 1st cell in the root hair cortex, through the plasma membrane.

Passes through plasmodesmata, to the cytoplasm of the next cell down the water potential gradient.

why can't the water just passes through the membrane ?

Because of the charged ion, it requires channel or carrier protein.

water move from one. cell to another, down a water potential gradient, across the phospholipid bilayer by osmosis.

why can’t mineral ions diffuses across the bilayer ?

Because mineral ion such as Mg 2+ hatwcarry a charge. This means that any water mineral ions needs an alternative way to travel to the xylem.

what is the function of apoplast pathway ?

Cellulose cell wall of plant are fully permeable to water so water carrying mineral ions can move through spaces in the cells wall without passing through the phospholipid bilayer.

Known as mass flow rather than osmosis and allow mineral ions to move with the water

what is the function of vacuolar pathway ?

Water can pass through the vacuoles.

A layer in the endodermis called ( Casparion strip ) stops water from entering the xylem through the apoplast ( cell wall ) pathway.

Must enter through symplast pathway.