Chapter 24

Question 1

Autotrophic

Answer 1

Make their own

Question 2

Heterotrophic

Answer 2

Humans - cannot make our own food

Question 3

Turgid

Answer 3

Cytoplasm swells with H2O
Cytoplasm presses on the cells wall

Question 4

Plasmolysed

Answer 4

Cytoplasm loses H2O
Cytoplasm pulls from cell walls
Plant wilts

Question 5

How does water get into the root hairs?

Answer 5

Osmosis
Water passes across ground tissue and into xylem vessels

Question 6

Root hair adaptations?

Answer 6

Thin walled and numerous

Question 7

Transport of water in a plant

Answer 7

Root pressure—> water is forced upwards

Transpiration—> loss of water vapour from a plant

Question 8

Cohension-Tension Model

Answer 8

Dixon and Joly
How water goes against ‘gravity’

Question 9

Cohension-Tension Model Summary

Answer 9

Water enters the roots through osmosis resulting in a build up of pressure in the xylem

Transpiration from the stomata cause the water molecules to evaporate

The water molecules join together due to the attractive forces

Transpiration and Cohesion cause the water molecules to be pulled upwards resulting in tension in the xylem

The water molecule,s cling together = adhesion

Question 10

Too much transpiration..?

Answer 10

Causes plant to wilt

Question 11

When is the rate of transpiration higher?

Answer 11

Hottest and sunniest weather

Question 12

How does the plant counteract the loss of water?

Answer 12

Guard cells
Cuticle
Stomata

Question 13

Guard cells

Answer 13

Close the stomata