mass movement in plants

Question 1

describe the movement of water from the root hair into the centre of the root from the phloem

Answer 1

-water travels through the apoplastic way till it reaches the endodermis.
-the endodermis has a casparian strip -which is a waterproof strip that restricts the movement of water molecules through the wall of the endodermis.
-water with ions is forced to move through the cytoplasm of the cell of the endodermis,
-the cells of the endodermis actively transport ions into the xylem by using carrier proteins
-this lowers water potential in the xylem causing water to move into the xylem from the endodermal cells down a water potential gradient .
-this enables water from the root hairs to move into the centre of the root by osmosis, down a water potential gardient.

Question 2

describe and explain the two pathways for phloem cells

Answer 2

-symplastic: the slower way as it moves through the cytoplasm across the membrane via osmosis

-apoplastic: the faster way as it moves along the cellulose walls via diffusion