3.1.3 Plant Transport – Movement of Water Through Plants

Question 1

By what process does water enter the roots?

Answer 1

Osmosis

Question 2

Describe how the root hair cells are adapted to maximise water uptake at the root.

Answer 2

• Large surface area
• Thin cell wall
• Low water potential

Question 3

Name the different cell types that water has to travel through in the root in order to get to the xylem.

Answer 3

1) Epidermis (root hair cells)
2) Cortex cells
3) Endodermis
4) Pericycle

Question 4

Describe the movement of water through the symplast pathway.

Answer 4

• Water travels through cell surface membranes and cytoplasm of the root cells.
• The water travels through the plasmodesmata to get from one cell to the next.

Question 5

Name the pathway that water takes when travelling through cell walls of the root cells.

Answer 5

Apoplast

Question 6

Name the impenetrable barrier found in the endodermis

Answer 6

The Casparian strip

Question 7

What is the Casparian strip made of?

Answer 7

It is made from a waterproof substance called suberin.

Question 8

What happens to water in the apoplast pathway once it reaches the endodermis?

Answer 8

Once the water reaches the waterproof Casparian strip endodermis, it is diverted to the symplast pathway, so it moves into the cytoplasm in order to reach the xylem.

Question 9

Why is it important that water is diverted at the endodermis?

Answer 9

To ensure that water moves through the cell membrane to control what enters the xylem.