lecture 13, Vasculature Flashcards
what two things make up the vascular system?
xylem and phloem
the body plan is composed of….(example from a generic angiosperm)
an apical-basal pattern, a radial pattern, and three tissue systems (epidermis, ground tissue, and vascular tissue)
what is the meristem?
a section of the plant where constant cell division occurs - a continuing source of new cells
what does the apical meristem give rise to?
protoderm, ground meristem, and procambium (the primary meristems)
what do the primary meristems give rise to?
primary tissues:
protoderm –> epidermis
ground meristem –> ground tissue
procambium –> primary xylem and primary phloem (vascular tissue system)
what is xylem and what is it responsible for?
water conducting cells, responsible for conduction of minerals and water, support, and food storage
primary xylem comes from…
procambium
secondary xylem comes from…
vascular cambium
what kind of growth do most plants exhibit?
primary growth
what plants exhibit secondary growth
gymnosperms and other woody plants
eg) conifers
what two lateral meristems are responsible for secondary growth
vascular cambium and cork cambium
what are the cell types in secondary xylem?
tracheids and vessel elements - both have secondary cell walls and lack protoplasts at maturity
what are the supporting tissues in secondary xylem?
fibers and parenchyma
how are tracheids made up?
made up into structures called pits. pits are thin modified primary cell walls. prevents air bubbles from forming
how are vessel elements made up?
made up of perforation plates, areas lacking primary and secondary cell wall. they are ladder-like scalariform or a single large opening