Plant Transport Definitions

Question 1

Bulk flow

Answer 1

The combined movement of water molecules and solutes together, due to a pressure gradients. Occurs in soil, xylem and in cell walls

Question 2

Xylem sap

Answer 2

Sap carried by the xylem, comprised mainly of water and inorganic ions

Question 3

Osmosis

Answer 3

Diffusion of water through a semi permeable membrane into a region of high solute concentration

Question 4

Water potential

Answer 4

Potential energy unit volume relative to water in reference conditions

Question 5

Aquaporin protein

Answer 5

Integral membrane proteins that serve as channels in the transfer of water, and in some cases small solutes across the membrane

Question 6

Plasmolysis

Answer 6

The separation of the plant cell cytoplasm from the cell wall as a result of water loss

Question 7

Flaccid cell

Answer 7

A plant cell that is limp through a reduction of turgor pressure inside the cell through loss of water

Question 8

Tonoplast

Answer 8

The cytoplasmic membrane surrounding the vacuole, separating the vacuolar contents from the cytoplasm in the cell

Question 9

Turgor pressure

Answer 9

Pressure exerted on a plant cell wall by water passing into the cell by osmosis, pushing the plasma membrane

Question 10

Casparian strip

Answer 10

Band of suberin and lignin on the radial and transverse walls of the endodermis that block the passive flow of materials into the stele of the plant

Question 11

Apoplastic pathway

Answer 11

Pathway taken by water from the root hairs to the xylem, through the cell walls and air spaces between cells

Question 12

Symplastic pathway

Answer 12

Pathway taken up by water through the cytoplasm and plasmodesmata continuum

Question 13

Endodermal cells

Answer 13

A single layer of modified parenchyma cells in the roots and stems of vascular plants forming the innermost layer of the cortex that helps regulate the intake of water and minerals into the vascular tissues

Question 14

Cohesion

Answer 14

The force of attraction between molecules of the same substance

Question 15

Adhension

Answer 15

Force of attraction between molecules of different substances

Question 16

Transpiration

Answer 16

Movement of water through plants and its evaporation from aerial parts

Question 17

Root pressure

Answer 17

Osmotic pressure within root cells with cause sap to rise through a plants stems to leaves.

The pressure occurs in the xylem of some vascular plants when the soil moisture levels are high at night. Or when transpiration is low during the day

Question 18

Guttation

Answer 18

The exudation (oozing) of drops of xylem sap on the tips or edges of leaves due to root pressure