3.1.3 - Transport in Plants Flashcards
What distinguishes stems from other parts of the plants
Presence of nodes and internodes
Role of vascular cambium
Responsible for secondary growth and contains meristematic tissue
Functions of roots
Anchor the plant in the ground
Store excess carbs
Absorbs water and minerals
Role of parenchyma
Involved in respiration, photosynthesis, storage and secretion
Heavily lignified
What is collenchyna tissue made of
Collenchyma cells
Pectin
Cellulose
Role of collenchyma
Provide support
Expands as the stem grows
Role of endodermal cells
Regulates the substances that enter
What is pericycle made of
Parenchyma and sclerenchyma
Role of pericycle
Maintains meristematic activity
What is xylem tissue made of
Tracheids
Vessel elements
Parenchyma
Sclerenchyma
Embolisms
Air bubbles formed in plant capillaries
Ions needed by plants
NO3 ^2- Mg ^2+ PO4 ^3- K ^+ SO4 ^2-
What is the cortex made of
Parenchyma
Transpiration
Loss of water from leaves of a plant, occurs from underside of leaf (stomata)
Water moves from areas of high hydrostatic pressure to areas of low hydrostatic pressure
Functions of water in plants
Turgidity - keep stems and leaves rigid
Photosynthesis
Enzyme reactions - metabolic processes occur in solution
Transport - ions absorbed in solution and transported in xylem
Apoplastic pathway
Water moving from soil solution to root hair and across cortex to the xylem in the cell walls
Symplastic pathway
Water moving from soil solution to root hair and across cortex to the xylem through the cytoplasm and plasmodesmata
Vacuolar pathway
Water moving from soil solution to root hair and across cortex to the xylem through the vacuoles
Factors affecting rate of transpiration
Temperature
Humidity
Light intensity
Wind
Lignin
Causes spirals in xylem
Allows cells to stretch/expand
Adaptations of vessel elements
Hollow lumen
Perforated cell ends
Lignin for rigidity
Casparian strip
Controls amount of water coming in the endodermis
Factors affecting transpiration
Temperature
Humidity
Light intensity
Water potential gradient
Control variables when using potometer
Cut at an angle to increase SA of lumen
Bung to stop water evaporating
Assemble potometer underwater - prevents air from entering
Dry leaves - no water molecules blocking stomata
Functions of roots
Anchor the plant in the ground
Store excess carb reserves
Absorb water and minerals
Purpose of root hairs
Provide a very large surface area for uptake of water and ions
Why is the root tip covered by a cap of cells
Protects dividing cells of the top and lubricates root movement
Meristem in roots
Increase height of plants