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.