Download Plant tissues

Plant tissues
Asmaa alfarajeen
Heba Al-Tamimi 
Plant tissues
• A tissue :is a group of cells that perform a
common function
Plant tissues
Meristematic
tissues
Apical
meristems
Lateral
meristems
Permanent
tissue
Simple
Permanent
tissues
Complex
permanent
tissues
Protective
tissue
Epidermis
Cork
(phellem)
TYPES OF PLANT TISSUE

Meristematic tissue
Apical meristems
Lateral meristems

Permanent tissue
1. Simple permanent tissue
Parenchyma
chlorenchyma
Collenchyma
Sclerenchyma
2. Complex permanent tissue
Xylem
Phloem

Protective tissue
Epidermis
Cork (phellem) /Periderm
Meristematic tissue
 Meristematic tissues are composed of embryonic,
undifferentiated cells that play a critical role in plant
growth
 Have distinguish feature :




without any intercellular spaces
thin cell wall
large nucleus
small or no vacuoles
Meristematic tissues occur in two regions
 Apical meristem
growing points of stem and root
give rise to primary permanent tissue (primary growth)
 Lateral meristem
in cambium
producing secondary permanent tissues (secondary
growth)
Meristematic tissues – localized regions of
cell division
Apical Meristems
Primary or Transitional Meristem  Primary growth
Protoderm  gives rise to epidermis
Ground meristem  gives rise to ground tissue
o
Procambium  gives rise to 1 vascular tissue
Lateral Meristems
o
Vascular cambium  2 vascular tissue
Cork cambium or phellogen  periderm
Permanent tissue
 Simple permanent tissue




Parenchyma
chlorenchyma
Collenchyma
Sclerenchyma
 Complex permanent tissue


Xylem
Phloem
Monocot
Monocots stem C.S
Dicot
Dicots
Monocots
Dicot
Epidermis
Structure:
One cell thick covers the whole of the primary plant
body
Secrete a waxy substance to form a layer of cuticle
Function:
protection
Root hair
Parenchyma
Distribution
in cortex, pith & packing tissue of vascular
tissues ( xylem and phloem)
Shape
 usually spherical
 unspecialised cells
 thin cell wall
Function
 store food ( starch)
 Photosynthesis
 intercellular space around parenchyma cells
allow exchange of gases
 respiration
Parenchyma
thin walled & alive at
maturity.
Parenchyma
Chlorenchyma
parenchyma with numerous
chloroplasts (common in
leaves).
Collencyma
Distribution
outer region of cortex in young stems
Shape
shape similar to parenchyma but thickened cell
wall at he corners of cell
elongated
Collencyma
thick-walled but flexible and strong, usually right
below the epidermis of a leaf or stem, used
for support in stems and leaves of non-woody
or young plants.
Collenchyma
thick walled & alive at
maturity
Collenchyma
Sclerenchyma
Structure
 heavily thickened with deposits of lignin (a complex
substances with great strength in the cell wall), even
thickening of cell wall.
 mature sclerenchyma cells are dead
 (stained red under microscope)
Function
provide support
Sclerenchyma
2. Permanent Tissues
B. Complex/Conducting Permanent Tissues
 made of more than type of cell.
 include the xylem (vascular tissue),
phloem (vascular tissue)
Sieve Tube Element
Companion Cell
Xylem Vessel
Air Space
Compound plant tissue
Plant tissues consists of more than one types of cell
e.g. Xylem
consist of
parenchyma cells
fibres(elongated sclerenchyma cells)
vessels
tracheids
Xylem :
Function
provide mechanical strength
give support to plant
conduct water and mineral salts
Xylem tissues
transports water and
dissolved substances
This tissue is composed
of parenchyma, fibers,
vessels and/or tracheids,
and ray cells.
Phloem (Compound plant tissue )
Consist of:
 Parenchyma
 Fibers
 sieve tube element
 companion cells
Function
 translocation of food
 no mechanical function
Periderm
Woody Stems
WOODY DICOT STEM
Summer Spring
Wood
Wood
Phloem
Phloem
Fibers
Xylem
Ray
Cortex or
Phloem Ray
Pith
Cork
Cambium
Cork
Annual
Ring
Primary
Xylem
Secondary
Xylem
Vascular
Cambium
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