Transport in flowering plants

Question 1

What is translocation

Answer 1

sieve tubes carry food products like sucrose & amino acids from the leaves to all parts of the plant ; requires energy

Question 2

Mechanism of water transport up the xylem vessel

Answer 2

• root pressure
• capillarity
• transpiration pull

Question 3

What is transpiration

Answer 3

process during which water evaporates from the surface of mesophyll cells into the air spaces of the leaf followed by diffusion of water vapour through stomata into the surrounding atmosphere

Question 4

Importance of transpiration

Answer 4

• provides cooling effect on leaves by removing latent heat from them
• creates suction force ; transpiration pull that draws water along the xylem vessels
• mineral ions carried along transpiration stream to the leaves
• helps to supply water to all cells for metabolic processes & maintaining turgidity

Question 5

Wilting

Answer 5

transpiration rate exceeds rate of water uptake by roots
- lose turgidity
- become flaccid ; drooping stem & leaves

Question 6

Adaptations to reduce transpiration in plants growing in dry regions

Answer 6

• presence of thick waxy cuticle / hairy cuticle
• leaves of smaller sizes ; reduce SA
• leaves have needle shape / reduced to spines
• fewer stomata in leaves
• rolling up leaves trap water vapour over their SA