Transport in Plants Flashcards
Uptake of water by the root hair cell
Osmosis
Water movement through the root
Osmosis
Pathways
Pathway where water moves cell to cell via cell to cell
Apoplast
Pathway where water moves cell to cell via the cytoplasm and through plasmodesmata
Symplast
Pathway where water moves trough vacuole
Vacoula
Water movement up the xylem into the root and stem
Transpiration
Root pressure
Transpiration pull
Properties of water
Explain cohesion
tendency of water molecules to attract one another
Explain adhesion
tendency of water molecules to be attracted to molecules of different types
Water movement through the leaf
Osmosis
Diffusion
Define transpiration
loss of water vapor from plant leaves by evaporation of water of the surfaces of mesophyll cells followed diffusion of water vapor through the stomata
Examples of Xerophytes in Namibia
Quiver tree
Euphorbia
Nara plant
Baobab tree
How do Xerophytes reduce waterloss
Reduced stomata
Sunken stomata
Surface has hair to trap water vapor
Smaller leaves= smaller surface area
Thorns= reduce surface area
Thick cuticle reflect light
Conditions that affects the rate of transpiration
Temperature
Wind
Humidity
Light intensity
How and why does wilting occur
Rate of water loss is greater than the absorption of water
Soil lacks water
Shortage of water
Define translocation
The transport of organic molecules (sucrose+ amino acids) in the phloem from a region of production (leaves) to regions of utilization or demand in respiration or growth (flowers+ roots)
Translocation of pesticides
Sprayed onto the leaves, absorbed through the cuticle/ stomata into the phloem tubes.
Plant sucking pest suck poisonous sap from the phloem.
Companion cells are:
Living cells
Contain cytoplasm, a nucleus, and mitochondria
Metabolically active cells
Phloem sieve tubes are:
Living cells contain cytoplasm and organelles
Tubes are connected end to end for easy flow
Organelles are at the edge to give more space for movement
Have end wall with sieve plates
Xylem cells are:
Dead hollow cells
Elongated cells arranged end to end to form tubes for transport
No end wall for minimum resistance
No organelles to obstruct flow
Large lumen allows unrestricted flow
Cellulose lining for adhesion
Function of the epidermis
protects the tissue
Function of the endodermis
regulates the passage of water
Function of the cortex
stores starch
