Module 3 - Transport in Plants

Question 1

Transpiration

Answer 1

• Due to cohesion tension when water evaporates from (leaf) due to sun, humid or wind, such tension causes the water to pull eachother up towards the leaf
• their cohesive attraction causes a continuous column and flow of water

Question 2

Translocation

Answer 2

• is the loading of assimilates (sugars) into sieve tubes
• H+ ions are actively transported out of companion cells
• H+ ions diffuse back in because the concentration is too high but they do this after binding to a sucrose molecule
• H+ and sucrose move back in through a co-transporter protein
• Sucrose actively transports into sieve tube
• water potential in sieve tube decreases so water moves into sieve tube by osmosis from the xylem creating a high hydrostatic pressure at the source