Water tranposrt Flashcards
(21 cards)
what are the 2 types of vascular tissue
- xylem
transports water and minerals from the roots to the leaves - phloem
transports sugar solutions, nutrients, and hormones.
transports sugar solutions in both directions, from roots to leaves and leaves to fruit
xylem (characterstics)
dead at maturity to specialize in water transport, and doesn’t need active transport since water moves through osmosis
2 types
-tracheid’s
-vessel elements
phloem characterstics
alive at maturity
2 types
-sieve tube elements
-companion cells
seive tube elemts
-have cytoplasm but no nuclei to maximize space for sugar solutions and nutrients
- sieve plates: cell wall; they have perforations at the end of the cell to allow for sugars to pass through (sieve plates)
companion cell
- assciated with every seive tube elemet
-have organelles and nuclie that sieve tube elemtns is missing
-gives instruction to sieve tube elements and support
2 types of tranport needed
water and nutreints
diffsuion
the moment of particles from areas of high article concentration to areas of low particle concentration until equilibrium is reached
moving along concretion gradients
high –> low
-against connection gradients
–>low–> high
omsosis
diffusion of water molecules across a selectively permeable membrane
water tranport
xylem allows for water to be moved from roots up to stem
xylem in leaves
xylem in leaves branches off to veins
Ventilation depends on whether the plant is a monocot or a dicot
parallel: veins run along the central vein
palmate; veins branch from the main point
pinnate; veins branch of central vein
At the end of the vein in leaves, water and minerals are absorbed into the cell
where does most water go
most water leaves the plant via transpiration since it does not get use
what does water move against
evil gravity
-root pressure (positive pressure cause pushes water upwards)
-transpiration pull (negative pressure cause it exerts tension on water in xylem)
root pressure
- minerals enter from the soil into roots via active transport since roots often have a higher concentration of minerals than in the soil
-Water enters from the soil into roots via osmosis since the soil has a higher water concentration than the roots. water causes positive pressure in roots, which pushes water upwards in the plant
short plants: water
in short plants, root pressure always water to reach from the roots to the surface of the leaves
guttation
in humid environments where evaporation is low, water droplets form around the edges of leaves
cohesion tension model
In taller plants, root pressure is not enough to reach the leaves so the cohesion-tension model is used to allow water and minerals to travel up
consist of
-transpiration
-cohesion
-adhesion
transpiration
-evaporation of water through the stomata since most water does not get used
-creates negative pressure because it exerts pressure on water in the xylem, which reaches all the way to the roots and pushes water upwards to the stem
cohesion
The attraction of water molecules together through hydrogen bonds
-creates a column of water in the xylem which allows them to move together upwards against evil gravity
-allows for transportation pull because one water molecule moves upwards, causing a column of them so they can all move together against evil gravity
adhesion
the attraction of water molecules to other molecules
allows for water to ‘stick” to walls of the xylem
No tranpsitation pull?
-water is unable to reach the leaves, then the plant is unable to do photosynthesis and die, also the plant needs essential minerals
