The document explains the classification and functions of plant tissues, including protective, meristematic, mechanical/ground, conducting, and specialized tissues. It details the characteristics and roles of each type, such as the importance of the epidermis in protection, the roles of various meristems in growth, and the structure and function of xylem and phloem in conducting nutrients. Additionally, it discusses specialized structures like stomata, root hairs, and trichomes that aid in absorption and environmental response.

1. PLANT
TISSUES
JKS JACOB

2. INTRODUCTION
 Histology is the science that
deals with tissues.
 Tissues are group of cells,
having the same structure and
perform the same function.
 Five groups of plant tissues:
 Protective Tissue
 Meristematic Tissue
 Mechanical /Ground tissue
system
 Conducting Tissue
 Specialized Tissue

3. I. PROTECTIVE TISSUE
covers the surface of
leaves and the living cells
of roots and stems.
1.Epidermis
is a single layer of
closely packed cells.
covers and protects the
plant. It can be thought of
as the plant's "skin."
plant's leaves secretes a
coating called the cuticle
that helps the plant retain
water.
plantcellbiology.masters.grkraj.org

4. I. PROTECTIVE TISSUE
2. Periderm (bark)
 replaces the epidermis in plants that
undergo secondary growth.
 consists of cork cells and protects the plant
from pathogens, prevents excessive water
loss and provides insulation for the plant.

5.  II. MERISTEMATIC TISSUE
 is the tissue in most plants
containing undifferentiated cells
(meristematic cells), found in
zones of the plant where growth
can take place.
 3 types:
1. Apical meristem
2. Lateral meristem
3. Intercalary meristem

6. 1. APICAL MERISTEM
completely
undifferentiated
meristematic tissue
found in the buds and
growing tips of roots in
plants.
 to begin growth of
new cells in young
seedlings at the tips
of roots and shoots
 Shoot Apical
Meristem (SAM)
 Root Apical
Meristem (RAM)

7. Longitudinal section of
shoot tip.
Longitudinal section of a root tip.

8. 2. LATERAL MERISTEM
cylinders of meristematic cells in
woody stems and roots.
Responsible for secondary growth, an
increase in girth or diameter in stems
and roots of many plants, mostly are
dicots.
It is due to the activity of two lateral
meristems.
Vascular cambium
Cork cambium

9. 2. LATERAL MERISTEM
1. Vascular cambium-
increase the thickness,
or girth, of the plant.
produces secondary
xylem and secondary
phloem.
does not occur in
plants that do not go
through secondary
growth (known as
herbaceous plants).
2. Cork cambium- gives
rise to the periderm,
which replaces the
epidermis.
Primary
phloem Primary
xylem
Secondary
phloem
Secondary
xylem
Annual
growth
layers
Lateral
meristems
Primary
xylem
Primary
phloem
Bark
Epidermis

10. Primary and secondary growth in stem.
MERISTEM

11. 3. INTERCALARY MERISTEM
found in grasses and related
plants that do not have a
vascular cambium or a cork
cambium, as they do not
increase in girth.
have apical meristems and in
areas of leaf attachment,
called nodes
produce new cells
responsible for increases in
length.
responsible for the regrowth of
cut grass.

12. III. MECHANICAL/GROUND TISSUE
Synthesizes organic compounds,
supports the plant and provides storage
for the plant.
made up of parenchyma cells but can
also include some collenchyma and
sclerenchyma cells as well.
Made up of:
Parenchyma
Collenchyma
Sclerenchyma
www.mindset.co.z

13. 1. PARENCHYMA
most abundant of cell
types
found in almost all
major parts of higher
plants.
cells are basically
sphere shaped
vital in repairing
damage to plant
tissues.
www2.estrellamountain.edu
intranet.tdmu.edu.ua

14. 1. PARENCHYMA
Chlorenchyma-
parenchyma cells that have
many chloroplasts and
form the tissues found in
leaves for photosynthesis
Parenchyma tissues
without chloroplasts are
generally used for food or
water storage.
Aerenchyma- groups of
cells that are loosely
packed together with
connected air spaces, such
as in water lilies.
sydney.edu.au
forestandrange.org

15. 2. COLLENCHYMA
is the increased
thickness of their walls.
found just beneath the
epidermis and generally
they are elongated
walls are pliable in
addition to being strong
provide flexible support
for organs such as
leaves and flower parts
 ‘strings’ from celery
that get stuck in our
teeth
www.meritnation.com

16. 3. SCLERENCHYMA
cells have thick, tough secondary walls
that are imbedded with lignin.
sclerenchyma cells are dead and function
in structure and support.
Sclerenchyma cells can occur in two
forms:
1. Sclereids
2. Fibers
cbseadda.blogspot.com
www.meritnation.com

17. 3. SCLERENCHYMA
1.Sclereids
providing structural
support and strength
to tissues
gritty texture in
some types of pears.
sometimes called
stone cells.

18. 3. SCLERENCHYMA
2.Fibers
found in roots, stems,
leaves and fruits.
much longer than they
are wide and have a very
tiny cavity in the center
of the cell.
used in the manufacture
of textiles, ropes, string
and canvas goods to
name a few.
https://en.wikipedia.org
admet.com

19. IV. CONDUCTING TISSUE
xylem and phloem
1. Xylem
tissue that conducts
the sap obtained by
absorption of water
and minerals by roots.
to conduct water and
minerals from roots to
other plant organs.
http://biology-igcse.weebly.com/

20. IV. CONDUCTING TISSUE
1. Xylem components:
Tracheids- are elongated
cells that serve in the
transport of water and
mineral salts.
providing structural support
Vessels- is the water
transporter of plans.
Xylem parenchyma– for
storage of reserve food.
Xylem fiber- for providing
mechanical support to the
essential elements.

21. IV. CONDUCTING TISSUE
2. Phloem
 tissue that conduct
the sap containing
water and amino acids
and sugars, especially
sucrose, obtained by
photosynthesis.
 to conduct
metabolites, amino
acids and sugars,
mainly sucrose, from
metabolite sources
(production sites) to
metabolite sinks
(consumption sites).

22. IV. CONDUCTING TISSUE
2. Phloem components:
Sieve tube- sieve plates — end walls — have
pores to facilitate flow of fluid between cells
Companion cell- nucleated cells connected to the
sieve-tube
help sieve tubes

23. IV. CONDUCTING TISSUE
2. Phloem
components:
Phloem
parenchyma – for
food storage.
Phloem fiber- to
provide
mechanical
support to plants.

25. V. SPECIALIZED TISSUE
1.Stoma (stomata)
Guard cells- pair of
specialized epidermal cells
act as a turgor-driven
valve that open and close
the pores in response to
given environmental
conditions.
 carbon dioxide enters;
oxygen exit
Water vapor is released
into the atmosphere
through these pores in a
process called
transpiration.

26. 1. STOMATA
Types based on
location:
Epistomatic- having
stomata on the upper
surface only
Hypostomatic- having
stomata (mostly) on the
underneath (foliar abaxial
surface)
Amphistomatic- having
stomata on both sides

27. Anomocytic- subsidiary
cells cannot be distinguished
from the ordinary epidermal
cells
Paracytic- longitudinal axis
of subsidiary cells is parallel
with those of the guard cells
Diacytic- longitudinal axis
and the common wall of
subsidiary cells is
perpendicular to those of the
guard cells.
Anisocytic– three subsidiary
cells, one being smaller or
larger than the other ones.
Number and Position of Subsidiary Cells
Actinocytic– four or
more subsidiary cells,
elongated radially to
the stomata

28. V. SPECIALIZED TISSUE
2. Root hairs
uncutinized epidermal
appendages
water and nutrient
absorption
increase water absorbing
capacity of the root
SIMPLE HAIRS
Theobrama cacao

29. V. SPECIALIZED TISSUE
3. Trichomes
cutinized epidermal
appendages found in
the leaf, stem, flower
and fruit
serve to protect and
prevent evaporation of
water.
unicellular or
multicellular.
TUFTED
Muntingia calabura Linn.
BRANCHING
Vervascum thapsus L.

30. TRICHOMES
BRISTLE
Chrysophyllum cainito Linn.
Psidium guajava L.
GLANDULAR
Muntingia calabura Linn.
STINGING
Laportea meyeniana L.
STELLATE
Solanum melongena L.
SCALE
Eleagnus philippinensis

31. CORN (MONOCOT)
STEM
Aristolochia elegans
(DICOT) OLD STEM
Epidermis
Vascular
bundles
Ground tissue
Pith
Cortex
Xylem Phloem
Sclerenchyma

32. FIRST TERM
QUIZ MARCH 2