Plants

Question 1

What are the two ways that water can travel through the roots?

Answer 1

The symplast system and the apoplast system.

Question 2

Symplast system

Answer 2

Some water moves through the root vie the cytoplasm of the root hair cells. The water has to cross the cell membrane, which regulates the passage of water and dissolved minerals.

Question 3

Apoplast system

Answer 3

• The water moves through the cell walls and the spaces between the cells.
• There are no membranes to regulate the passage.

Question 4

Why can water easily move through xylem tissue?

Answer 4

The cells that make up the xylem tissue are dead, waterproof and hollow.

Question 5

How is water pulled up through the xylem tissue?

Answer 5

1) Water evaporates from inside the leaf to a higher concentration of solutes.
2) Water from the nearest xylem vessel enters by osmosis
3) Water molecules stick together because of weak hydrogen bonds between them - this is called cohesion
4) As water molecules leave the xylem vessel they pull up further molecules, so the whole column of water is pulled up.
5) Evaporation pulls the water column upwards and gravity pulls it down, so the water column is under tension
6) The adhesion of water molecules to the sides of the xylem vessels stops the column breaking

Question 6

Translocation

Answer 6

Translocation is the movement of carbohydrates and other organic compounds in plants

Question 7

Where does translocation occur?

Answer 7

In the sieve tubes of the phloem tissue

Question 8

In the symplast system, which part of the cell does water move through?

Answer 8

Cytoplasm

Question 9

Why is the column of water in the xylem under tension?

Answer 9

Evaporation is pulling the water column up and gravity is pulling it down.

Question 10

What substances are transported in the phloem tissue?

Answer 10

Sugars and other organic compounds.