vascular tissue in plants Flashcards
what is vascular tissue
complex tissue in plants which transports fluids and nutrients around the plant
what does the xylem transport
transports water and mineral ions
what does the phloem transport
organic substances (sucrose and amino acids)
what are vascular bundles and where are they found
xylem and phloem run close to each other
stems and leaves
where are stele found
roots
what do vascular bundles form in leaves
the mid rib and the veins
what is the function of the xylem
tissue that transports water and mineral ions from the roots to the leaves
in addition it provides strength and support to the plant
what is the structure of the xylem
xylem undergoes secondary thickening on its cell wall
a waterproof substance called lignin is deposited in a thick layer inside the cellulose cell wall
water and nutrients can no longer enter the cells and its contents die
the deal cells are hollow which allows them to act as tubes to transport water and mineral ions
there are two types of xylem - vessels and tracheides
what are xylem vessels
found only in angiosperms
the end walls of the cells break down so the cells are effectively hollow tubes
water travels easily from one cell to another
lignin is laid down in a variety of patterns which strength the cell
holes (pits) in the wall allow water to move to adjacent cells
what are xylem tracheids
found in flowering plants conifers ferns. not found in moss
they are long thin cell with tapering end walls
they also have pits in their walls
what is transpiration
plants take in water through their roots in the soil and is lost through the leaves in the transpiration steam
water enters the plants through the root hairs moving down a water potential gradient because the vacuoles of root cells contain a strong solution of dissolved substances hence a lower water potential than the soil
what is the water movement in the roots
water enters the root through the epidermal cells of the root
some of the cells are elongated into root hairs
what route is apoplast
between the root cells along the cell walls
what route is vacuolar
from vacuole to vacuole
what route is symplast
through the cell membranes cytoplasm or plasmodesmata
