Semester 1 Final: Transport in Vascular Plants

Question 1

Material Transport in Plants

Answer 1

 Transport of water &
solutes by individual cells
 Short distance transport
at the tissue & organ
level
 Long distance transport
through the xylem &
phloem across the entire
plant

Question 2

Water’s Pathway: soil to xylem

Answer 2

 Soil to epidermis: water & mineral salts enter through root epidermis with the aid of root hairs & mycorrhizae
 Epidermis to root cortex to xylem

Question 3

Water’s Pathway: Xylem to leaves

Answer 3

 The transpiration-cohesion-tension mechanism is the main source of water’s movement
 Transpirational pull: the outside air has lower Ψ than air in the leaf which results in diffusion of water vapor from the leaf & evaporation
 Lost water is replaced by water in the xylem due to cohesion which pulls water molecules one by one the entire length of the plant
 Requires no energy!

Question 4

STOMATA & TRANSPIRATION

Answer 4

 The large surface area of a leaf is advantageous for photosynthesis, but water is lost through stomata
 Thankfully, guard cells cause them to open & close in response to stimuli

Question 5

Lateral transport

Answer 5

Short distance movement through plant tissues

Question 6

TRANSPORTATION OVER LONG DISTANCES

Answer 6

Bulk flow of fluid through the whole plant
 Water & solutes move through the xylem
 Sugars move through the phloem

Question 7

transpiration

Answer 7

movement of water up the xylem and evaporation from the stomata in plants