How does water travel from the soil into a plant's roots, and from there all the way up the stem?
Root hair cells have a higher solute concentration than the surrounding soil water, so water moves into them by osmosis, across the cell membrane.
Why does water move from the soil into root hair cells, rather than the other way around?
Because the root hair cell's cell sap is more concentrated than the soil water, so water moves in by osmosis, from an area of higher water concentration to lower
Water travels from the root hair, through the cortex, across the endodermis, and finally into the xylem vessels, where it is transported upward through the plant.
List the correct order water travels through, from the soil to the xylem.
Root hair → cortex → endodermis → xylem
1. By what process does water enter a root hair cell?
2. What structure do root hair cells belong to, that increases the surface area for absorption?
3. Name the layer water crosses just before entering the xylem.
4. What is the function of the xylem?
5. Why do root hair cells need a higher solute concentration than the surrounding soil water?
6. What is active transport?
7. Why do minerals often need active transport to enter root cells?
8. Is osmosis a passive or an active process?
9. What is the name of the pressure that pushes water up from the roots?
10. Why might a plant wilt in very salty soil even if the soil is wet?