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Chapter 6:Tissues and the primary growth of Stems - Coggle Diagram
Chapter 6:Tissues and the primary growth of Stems
Concept
Parts of herb
leaves, stem and root
Angiosperm
flowering plant
Eudicots
Broads leaf plants such as roses, asters, maples
monocots
grasses, lilies,cattails, palms,philodendrons, bromeliads
Types of plant body
Primary
derived from shoot and root apical meristems
composed of primary tissues: epidermis, cortex,pith and others
Secondary
Derived from meristems other than apical meristem
composed of secondary tissues: wood and bark
Basics types of cell and tissues
collenchyma
uneven thicken primary walls
typically alive at maturity
provide plastic support
Require more glucose for their production
present in elongating shoot tips that must be long and flexible such as vining plants like grapes
sclerenchyma
primary wall plus secondary wall
many dead at maturity
provide elastic support and some are involved in water transport
Types of sclerenchyma
mechanical
sclereids
More or less isodiamerric, often dead at maturity
fibers
long, many types are dead other remain alive and involve in storage
tracheary element
tracheids
long and narrow with tapered ends
contains no perforations
dead at maturity
found in all vascular plants
vessel elements
short and wide with rather perpendicular end walls
most contain one or two perforations
dead at maturity
found almost exclusively in flowering plants
among non flowering plants, only a few ferns, horsetails, and gymnosperms have vessels
Parenchyma
Thin primary walls.
Typically alive at maturity
soft leaves, petal, fruits and seeds are almost completely composed of parenchyma
Types of parenchyma tissue
chlorenchyma
involve in photosynthesis
consists of neumorous chloroplast
glandular
secrets nectar, fragrance, mucilage, resins and oil
few number of chloroplast
have elevated amount of dictyosomes and endoplasmic reticulum
transfer cell
mediate short distance transport of material by means a large, extensiveplasma membrane capable of holding nemerous molecular pumbs
External organization of stems
nodes
where leaves are attached
internodes
regions between nodes
Leaf axil
stem area where leaf attaches
Axillary buds
a miniature shoot within an dormant apical meristem and several young leaves
bud scales
protect the delicate organ of bud
terminal bud
located at the extreme tip of each stem
Phyllotaxy
arrangement of leaves on the stem
alternate
leaves one per node
opposite
leaves two per node
decussate
leaves located in four rows
whorled
three or more leaves per node
spiral
leaves not aligned with their nearest neighbors
Distichous
leaves located in two rows only
Bulbs
Short shoots that have thick, fleshy leaves
corms
verticle thick stem that have thin, papery leaves and gladiolus
Aggangement of primary tissue
Epidermis
Outer surface of an herbaceous stem
single layer of living parenchyma cell
Special chemicals in walls
Cell type: collenchyma; chemical: pectin; proprety: plasticity?
Cell type: Sclerenchyma; chemical: ligin; property: strength and waterproofing
cell type: Epidermis; chemical:cutin; propert: indigestible by bacteria, fungi and animals
celltype: endodermis; chemical: suberin and lignin; property: waterproofing
cell type: Cork; chemical: suberin; property: waterproofing
Cutin
The outer encrusted tangential wall
stoma
guard cells and stomal pore together
stomal pore are opened during daytime permiting carbondioxide inside the plant
Cortex
Interior of the epidermis
composed of photosynthetic parenchyma and sometimes collenchyma
vascular tissues
Consists of vascular system by which water and nutrients are conducted throughtout the plant.
types
Xylem
Two conducting cells
tracheids
long and narrow
ends pointed
Vessel elements
Short and wide
ends usually flat
Phloem
Types of conducting cells
sieve cells
long and narrow
Ends pointed
Sieve tube membrane
Short and wide
Ends usually flat
Vascular Bundles
Xylem and phloem together
Located interior the cortex
collateral: each contains both xylem and phloem strands running parallel to each other
Primary xylem: xylem of vascular bundle
primary phloem: Pholem of vascular bundle
Stem growth and differentiation
Apical meristem
stems that grow longer by creating new cells at their tipsin shoot
subapical meristem
region just below the apical meristem
cells are dividing and growing, producing cells for the region below
Protoxylem
first formed part of the xylem
metaxylem
forms later
Protophloem
formed from the procambium meristem
metaphloem
originated from the fasicular cambium meristem
Angular thickenning
provide large surface area for water movement
helical thickening
secondary wall exists as one to three helices interior to the primary wall
Sclariform thickening
provide much more strenght
reticulate thickening
secondary wall is deposited in the shape of a net
