transport in plants Flashcards
(18 cards)
why do plants need a transport system
-large plants have a small SA:V ratio
-need to have specialised exchange surfaces and transport medium
Why cant some plants live without transport system
-plants aren’t very active (low respiration) and demand for o2 is low (diffusion)
-but demand for water and sugars is still high (phloem and xylem)
what kind of plant do we look at the distribution of vascular tissue in
-Dicotyledonous plants (two seed leaves)
where are xylem and phloem found
-together in vascular bundles
-these may contain other types of tissues like collenchyma and sclerenchyma
-to give bundle strength and support
in a dicot root, where are xylem tissues found
-in the central core, in an X shape
in a dicot root, where are phloem tissues found
-between the arms of the X (xylem)
how does the arrangement of vascular bundles benefit a dicot root
-provides strength to withstand pulling forces
what is found around the vascular bundle
-the endodermis
-inside this is the pericycle
what is the pericycle
-layer of meristem cells inside endodermis
in a dicot, non woody stem, where are vascular bundles found
-around the outer edge of the stem
-they are separate and discrete
in a dicot, woody stem, where are vascular bundles found
-near the outer edge of the stem
-separate in young stems
-continuous ring in older stems
in the dicot stem, what is the arrangement of the vascular bundle
-xylem inside
-phloem outside
-cambium separating the two
what does the cambium contain in plants
-meristematic cells
in a woody plant, how does the ring of vascular bundles benefit them
-arrangement allows strength and flexibility to withstand bending forces
what do vascular bundles in the leaf form
-vascular bundles form mid rib and veins
in a dicot leaf, what is the arrangement of mid rib and veins
-branching network of smaller veins
arrangement of xylem and phloem in veins
-xylem on top
-phloem on bottom
how does the casparian strip block ions
-strip is impervious to water
-forces water through the plasma membrane
-phospholipid bilayer repels charged particles so they wld need a channel
