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Transport process in plants - Coggle Diagram
Transport process in plants
Transpiration
Importance of transpiration: wilting
What is wilting?
Leaved fold due to loss of water
Advatages
Rate of transpiration reduced
Leaves fold to reduce surface area exposed to the sun
Guard cells become flaccid (stomata close) to prevent water loss
Disadvantages
Rate of photosynthesis is reduced
Water becomes limiting factor
Closed stomata reduce CO2 levels
Transpiration pull: water moves up column from roots to leaves. Water is transported up plant. Plant has to lose water to gain water
Factors
humidity of air
More humid= slower transpiration
Temp. of air
Higher temp.= higher rate of evaporation= more transpiration
Wind
Stronger wind= higher rate of transpiration
Light
Affects size of stomata-> presence of light= increase of transpiration
Dependent upon evaporation
Means: loss of water vapor from aerial parts of plant, especially through stomata of leaves
Phloem
Adaptations
Holes in sieve plates allow substances through sieve tube cells
Functions
Transports food from leaves to rest of plant
Sucrose and amino acids also stored in fruits
Structure
Has sieve cells that allow s food using osmosis
Companion cells provide energy for sieve cells as transport of food requires energy
Xylem
Structure
Walls made of lignin
Consists of mainly vessels
Pits allow water and dissolved minerals to be transported sideways to other cells
Stretches from roots to leaves
Adaptations
Lignified walls for support
Hollow lumen with no cross walls for water to pass through easily
Dead with no protoplasm (hollow lumen)
Functions
Provide mechanical support
Transport water from roots to rest of plant
Movement of water
Water enters plant through roots through osmiosis
Cell sap in root hair has lower water potential than surrounding soil solution, so water enters through osmosis
Water passes by osmosis from root hair cell to inner cells
Process continues until water reaches xylem vessels to be transported through plant
Manufactured food substances
Transported as sucrose and amino acids
Translocation
Active process that requires energy