multicellular organisms-plant transport Flashcards
what is the vascular bundle/vein?
it is the transport tissue in plants, which is made up of xylem and phloem
what is the palisade mesophyll?
main photosynthesis cells in a leaf, large cells arranged at the top of the leaf to maximise light exposure
what is evaporation?
when water changes to water vapour
what are guard cells?
they control the opening and closing of the stoma
what is transpiration?
the process of water moving through a plant and its evaporation through the stomata
what is the stomata?
it is the pores in leaves where water is lost by evaporation and gas exchange takes place
what is the spongy mesophyll?
it is the photosynthetic cells found below the palisade mesophyll in leaves, surrounded by air spaces. it also carries out gas exchange with the air spaces
what is the upper epidermus?
it is the upper surface of leaves, which has transparent cells to allow light through to photosynthetic cells
what is the lower epidermus?
the lower surface of leaves which contain the stomata
what are root hair cells?
they are cells with increased surface area for water absorption from the soil
what is the xylem?
it is the transport tissue for water and minerals through the plant to the leaves. they are dead, hollow tubes thickened with spirals of lignin
what is lignin?
spirals which coat the inside of xylem vessels to strengthen and support the xylem vessel
what are sieve tubes?
they are part of the phloem vessel, and they allow sugar to be transported through it
what is the phloem?
living transport tissue for sugar. sieve tubes attached to companion cell
what are the factors which affect the rate of transpiration?
-wind speed
-humidity
-surface area
-temperature
what is transported up and down in living phloem cells?
sugar
what is the structure of plant cells?
-Upper epidermus
-Palisade mesophyll
-Spongy mesophyll
-Guard cells
-Stomata
-Vein
-Lower epidermus
how does water enter root hairs?
by osmosis
what do the rings of lignin around the xylem do?
they stop the tube from closing under the pressure of the water
describe water movement in a plant:
-water moves into the root hairs by osmosis, it then travels upwards to the leaves in the xylem, then it travels to the stomata where it evaporates
what happens to the rate of transpiration when the wind speed increases?
transpiration rate increases
what happens to the rate of transpiration when the temperature increases?
transpiration rate increases
what happens to the rate of transpiration when the surface area increases?
transpiration rate increases
what happens to the rate of transpiration when the humidity increases?
transpiration rate decreases
what happens to the rate of transpiration when the wind speed decreases?
transpiration rate decreases
what happens to the rate of transpiration when the temperature decreases?
transpiration rate decreases
what happens to the rate of transpiration when the surface area decreases?
transpiration rate decreases
what happens to the rate of transpiration when the humidity decreases?
transpiration rate increases
what can the rate of transpiration be measured by?
a potometer
what are the 2 types of potometer?
a mass potometer, and a bubble potometer
how does a mass potometer work?
as water evaporates from the surface of the leaves the water loses mass, the faster the rate of transpiration, the more mass the shoot will lose in a given time
how does a bubble potometer work?
as water moves up through the plant the air bubble moves along the scale giving a measure of water absorbed by the plant over time and hence the transpiration rate
why is there a layer of oil over the water the shoot is sitting in in a mass potometer?
to prevent the water evaporating from the soil
what does sugar give plants?
it gives plants the energy required for growth and repair
what direction does the xylem transport?
ONLY UPWARDS
what direction does the phloem transport?
both upwards and downwards
if the guard cell is turgid…
the stomata is opened
if the guard cell is flaccid…
the stomata is closed
