Plant Transport Tissues & Mechanisms - exam practice

the movement of H⁺ ions from companion cells

the movement of H⁺ ions into companion cells

the movement of sucrose from companion cells

the movement of sucrose into companion cells

1, 2, and 3

2, 3, and 4

1 and 3 only

1 and 4

lignin forms an incomplete secondary wall

new vessels carry extra water as a plant grows

there are no cross walls between vessel elements

vessel elements join to form narrow tubes

1 only

3 only

2 and 3 only

1, 2, and 3

increasing the humidity

increasing the light intensity

decreasing the temperature

decreasing the wind speed

cells joined to form a tube, pits at intervals, sieve plates between cells, surrounded by the endodermis in roots

contains cells joined end to end, containing cytoplasm, cell walls with lignin, located to the outside of phloem in vascular bundles

contains elongated cells with end walls broken down, located in vascular bundles in the stem and centrally in the roots

dead elongated cells, lignified cell walls with pits at intervals, associated with companion cells in the roots only

diffusion of water from intercellular air spaces to the atmosphere where it evaporates

evaporation of water from the leaf surface of a plant via the stomata

loss of water vapour from the aerial parts of a plant to the atmosphere

movement of water from the xylem to the atmosphere through the cell walls only

active transport

diffusion

facilitated diffusion

mass flow

moving sucrose into the sieve tube element

removing protons out of the cytoplasm of the companion cell

removing protons from the sieve tube element

taking up sucrose into the cytoplasm of the companion cell

1 and 3

2 and 3

1 only

2 only

1, 2, and 3

1 and 2 only

1 and 3 only

2 and 3 only

sucrose actively loaded into sieve tube elements decreases the water potential causing the hydrostatic pressure to increase

sucrose actively loaded into sieve tube elements increases the water potential causing the hydrostatic pressure to decrease

sucrose diffused into sieve tube elements decreases the water potential causing the hydrostatic pressure to increase

sucrose diffused into sieve tube elements increases the water potential causing the hydrostatic pressure to decrease

on a humid day, the water potential gradient between the intercellular air space and the external atmosphere increases to stimulate water loss by evaporation

water arriving at the spongy mesophyll cells via the symplast pathway must move by osmosis through the cell surface membrane before evaporation from the surface of the cells

water diffuses down the water potential gradient from the saturated air space through the guard cells before evaporating from the surface of the cells into the atmosphere

water moves up the xylem in the apoplast pathway and can continue on this pathway by osmosis to reach the spongy mesophyll cells before evaporating into the intercellular air space