L7: Vascular Tissue System Flashcards
What primary tissue system does the procambium produce
vascular
Where is primary phloem and xylem derived from
procambium
where is secondary xylem and phloem derived from
the vascular cambium
What does the vascular tissue system consist of
xylem
phloem
parenchyma
sclerenchyma
How is vascular tissue arrangement different in monocots and dicots
is present as a ring in dicots, but randomly spread out in a monocot
vascular bundle
a strand of primary phloem and xylem often enclosed by a bundle sheath of parenchyma or sclerenchyma fibers
functions of the xylem
transport water and minerals
support (sclerenchyma)
storage (parenchyma)
cell types of xylem
tracheary elements called tracheids and vessel elements
tracheary elements cells criteria
cell wall: lignified secondary cell walls with lots of pits
cell shape: cylindrical with varied diameters
status at maturity: dead
cytoplasm: gone at maturity (PM gone as well)
distribution: in vascular tissue only
different perforation plates in vessel element end-walls
simple perforation plate (single hole)
compound perforation plate (several holes)
compared to tracheids, vessel elements are:
shorter and wider
better conductors
have perforation plates on end walls
more advanced
cell types in phloem
sieve tube elements
companion cells
phloem function
transport of sugars, nutrients, and signaling molecules
long-distance signaling
_____ supports diameter increase in plasmodesmata/pores
callose
sieve elements cell type criteria
cell wall: primary cell walls only with lots of plasmodesmata
cell shape: STE - cylindrical and elongated CC- elongated
status at maturity: alive
cytoplasm: STE filled with phloem sap CC - dense cytoplasm
distribution: vascular tissue only
how are sieve tube elements joined together
joined end to end by sieve plates to form continuous sieve tubes
sieve plate
portion of cell wall between adjacent sieve tube elements with many sieve pores
simple sieve plate
entire plate is a single sieve area
compound sieve plate
plate has multiple sieve areas
protoxylem
first to form
differentiation happens before elongation of the organ has completed
Metaxylem
forms later than the protoxylem
differentiation happens after elongation of the organ has completed
protophloem
first to form
differentiation happens before elongation of the organ has completed
metaphloem
forms later than the protophloem
differentiation happens after elongation of the organ has completed
