Transcript snowball flowers

Lecture 4
Anatomical structure of vegetative plants organ.
Plan
1. Anatomical structure of root.
2. Anatomical structure of stems and rhizomes.
3. Anatomical structure of leaves.
Prepare:
ass.
Kernychna I. Z.
These organisms
are composed of
an underground
root system and
an over ground
shoot system.
Monocots and dicots get their names because of
the number of cotyledons present in their seeds.
Monocots have one seed leaf or cotyledon while
dicots have 2 seed leaves or cotyledons.
BEAN seed is a dicot and
a CORN seed is a monocot
There are
quite a few
differences
between a
monocot and a
dicot plant.
This table
their
differences:
ROOT
In vascular plants, the
root is the organ of a
plant body that
typically lies below
the surface of the
soil.
Functions of roots are 1.)
absorption of water and
inorganic nutrients, 2.)
anchoring the plant body to
the ground, 3) often function
in storage of food
Roots of many plants use in medicine:
Cichorium intydus,
of althea (Althea officinalis
),
dandelion (Taraxacum officinale)
Long-section of root has 3 zone:
І. ZONES OF CELL
DIVISION
cap
with root
ІІ. Ellongation;
ІІІ. Differentiation
Or Maturation.
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Dermal tissue- such
as epidermis that
protects the plant.
Ground tissuetissue found between
the dermal and
vascular tissue. Serves
as structural strength.
Vascular tissuetissue that transports
material. Xylem
transports water and
phloem transports
food.
Primary
structure or root
(in cross sections of differentiation)
1) Epidermis with roots
hair
2) Cortex (parenchyma,
endodermis with
Casparian strip)
3) Vascular cylinder
(pericycle, xylem and
phloem forms radial
bundle)
Monocot roots
vascular bundle
is polyarch, closed,
and radial.
In dicot roots
with primary
structure
vascular bundle
is closed, radial,
and tetraarch.
In dicot roots, the xylem tissue
appears like a 3-pronged or 4pronged star
Dicot roots with secondary
vascular bundle structure have
opened collateral vascular
bundles in stele, which are
arranged in circle. Between them
there are wide medullary rays
which are start in primary xylem
and are situated in the center of
a root. Dicot roots with
secondary nonbundle structure
have solid ring of vascular
cambium, solid zone of phloem
above it and solid zone of xylem
below cambium. In the center
there is primary xylem. Primary
medullary rays stretch from it,
Secondary rays are formed by
cambium.
In most plants stems are located above the soil
In medicine use
herbs
many plants (stems with leaf,
flowers).
At some woody
plants use in medicine
(snowball tree, oak-tree )
primary bark (cortex)
Monocot Stem.
A cross section : 1) epidermis;
2) cortex (chlorenchyma and sclerenchyma);
3) Vascular cylinder (scattered vascular bundle is closed collateral.).
 Monocot
stems differ from dicot
stems in that they lack secondary
growth
 No vascular cambium nor cork
cambium
 Stems usually uniform in diameter
 Scattered vascular bundles (not in a
ring like dicot stems)
DICOT STEM:
1) Open collateral vascular bundle;
2) Under epidermis is collenchim,
not sclerencim
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A. epidermis (outermost layer of cells forming
the initial covering on a stem).
B. cortex (ground tissue that surrounds the
vascular cylinder or stele).
C. endodermis with Casparian strip (regulates the
flow of water and dissolved substances).
D. primary xylem (water-conducting tissue found
in the vascular cylinder or stele)
E. primary phloem (food-conducting tissue
found in the vascular cylinder or stele)
WOODY STEM:
1) The "bark" of the tree
consists of the periderm
+ the phloem ;
2) The vascular cambium
cells divide to produce
secondary xylem
to the inside and
secondary phloem to the
outside
Gymnosperm stems
1)Has
tracheids in
their xylem
2)Gymnosperm
wood also
often contains
resin ducts
A RHIZOME is underground modification of stem,
which is formed at
perennially herbacеous plants for an accumulation
nutritives and vegetative reproduction.
Has the well formed stocking parenchyma; mechanical and
vascular tissues are expressed poorly. In medicine use
rhizome of sedge cane, fern, valerian and other
Leaf– lateral vegetative organ of plants,
the general function its are photosynthesis, transpiration.
There are several types of leaves:
1) Bifacial)
2) Izolateral ;
3) Radial )
LEAF CROSS SECTION
Dermal Tissue: outer single cell
layer protective tissue.
Cuticle: layer of waterproof wax on
the outer surface of the dermal
tissue.
Ground Tissue: usually two layers,
closely packed upper layer and loose
lower layer – photosynthetic tissue.
Air Spaces: rapid diffusion of
carbon dioxide to the cells for
photosynthesis.
Guard Cells: control the closing and
opening of the stomatal pore.
Stomata: rapid entry of carbon
dioxide into the leaf from the air.
bifacial (common for dicot)
isolateral (common for
monocot and dicot
plants)
Radial (common for gymnosperm)