23 -1 Specialized Tissues in Plants
Roots
absorb water, anchor plant
three main tissue systems
dermal, vascular, and ground
tracheids
long, narrow cells that are impermeable to water. cells have pierced openings when mature they die and cytoplasm disintegrates.
sieve tube elements
main phloem cells. many small holes at bottom.
guard cells
on the underside of leaves on the dermal tissue.
leaves
where photosynthesis takes place
apical meristem
a group of undifferentiated cells that divide to produce increased length of stems and roots
differentiation
cells retaining special functions and purpose
meristems
clusters of tissues that are responsible for continuing growth throughout a plants life.
vascular tissue
contains several types of specialized cells. xylem consists of tracheids and vessel elements. Phloem consists of sieve tube elements and companion cells.
sclerenchyma cells
have extremely rigid and thick cell walls that make ground tissue tough and strong.
Parenchyma cells
have thin cell walls and a large central vacuoles w/ thin layer of cytoplasm main sites of photosynthesis in leaves
collenchyma cells
have thin flexible cell walls that support larger plants.
trichomes
help protect leaf and give it a fuzzy appearance
epidermal cells
outer covering of dermal tissue that usually consists of a single layer
Three Organs of plants
roots, stems, leaves
companion cells
surround sieve tube elements keep nuclei and other organelles support and aid in phloem transport
meristematic tissue
the new cells produced from meristems undifferentiated cells that have no specific function only plant tissue that produces that produce new cells by mitosis
stems
transport water and products of photosynthesis through xylem and phloem.
cuticle
waxy layer of epidermal cells protects against water loss and injury
vessel element
xylem cell in angiosperms wider than tracheids cell walls die and merge together forming one continuous cell.