Transport in Vascular Plants

Question 1

what is transported?

Answer 1

water
nutrients
sugar
hormones

Question 2

why are water plants better for transport?

Answer 2

water is everywhere so provides everything except sugars

Question 3

how do the roots work?

Answer 3

absorb water and nutrients from soil, specifically damp, nutrient rich soil
synthesis the correct proteins for absorption
respond to water/nutrient need
competition - distinguish between self and non self

Question 4

what do roots need?

Answer 4

bulk flow at high pressure from roots to leaves at low pressure

Question 5

difference between diffusion and active transport?

Answer 5

active needs energy and is low to high

diffusion passive and is high to low

Question 6

what is water potential?

Answer 6

flow from high to low

Question 7

what is pressure potential?

Answer 7

water pushing against sides in plants promoting tension so plant stiff
loss leads to wilting

Question 8

what happens to solute potential when high solute conc?

Answer 8

lowers

Question 9

water potential =

Answer 9

solute potential + pressure potential

Question 10

what are secondary metabolites?

Answer 10

defences usually chemical that deter herbivores, plants focus investment on toxins

Question 11

why are secondary metabolites necessary?

Answer 11

plants need to defend themselves as can’t run away

Question 12

what is automimicry?

Answer 12

when the herbivore overcomes toxin and can use it itself

Question 13

how do monarch butterflies feed on something other than milkweed?

Answer 13

learned aversion - but frequenty dependent

Question 14

how is water pulled up a plant?

Answer 14

against gravity due to difference in water pressure in leaves and rest of plant
cohesion of water and adhesion of xylen walls also helps

Question 15

what is the function of the xylem?

Answer 15

takes water from roots to leaves

Question 16

how does the xylem carry so much water?

Answer 16

secondary growth increases capacity of trunk and stems

Question 17

what is the function of the stomata?

Answer 17

minimising water loss

controlled by guard cells

Question 18

factors that affect opening/closing of stomata?

Answer 18

light, time, hormones when soil moisture low, wind

Question 19

function of the phloem?

Answer 19

carrys sugars up the plant - for respiration, storage, growth
bulk flow doesn’t require energy but active transport does to load sap into carbs

Question 20

how does the phloem work?

Answer 20

pressure driven, low at sinks, high at sources

Question 21

what is contained in sap and where is it found?

Answer 21

Phloem

amino acids, nutrients, glucose, hormones