plant biology Flashcards
the two type of transport systems in a plant
xylem and phloem
the function of xylem
transports water and minerals
function of phloem
transports sugars and amino acids dissolved in water
in the stem, what are the tissues of the xylem and phloem grouped in
vascular bundles
what are plant leaves adapted for
gas exchange and photosynthesis
the function of a large surface area
for maximum absorption of light; for optimum absorption of carbon dioxide
the function of air spaces between cells within the leaf
for the diffusion of gases
what do the palisade mesophyll cellls do and what do they contain
the palisade mesophyll layer of the leaf is adapted to absorb light efficiently. the cells:
are packed with many chloroplasts
are column-shaped and arranged closely together
towards the upper surface of the leaf
what is the transport of substances in the phloem is called translocation.
translocation
inside the plant how can the substances move into and around
diffusion and osmosis
what are root hair cells
root hairs are single-celled extensions of epidermal cells in the root. they grow between soil particles and absorb water and minerals from the soil
factors that affect transpiration
temperature, humidity, air movement and light intensity
how does an increase of temperature increase the rate of transpiration
increased molecular movement so that: more water molecules evaporate from cell surfaces; the rate of diffusion of water molecules from the leaf is increased
how does an increase of humidity affect the rate of transpiration
reduces the concentration of water molecules outside the leaf; diffusion of water from the leaf increases
how does an increase of air movement increase the transpiration rate
removes water vapour from leaf surfaces; more water diffuses from the leaf
