This document provides information on plant cells, tissues, and organs. It discusses the main tissue types found in plants, including meristematic, protective, parenchyma, sclerenchyma, collenchyma, xylem and phloem tissues. It also describes the structures and functions of stems, leaves, flowers, fruits, seeds and roots. Key parts of these plant structures are defined such as the epidermis, vascular bundles, bud scales, stomata and root hairs. The document provides diagrams to illustrate plant cell types and the internal structures of stems and roots.

1. Presented by: Group 6
Colapo, Wilson
Dulnuan, Johndy
Galino, Ramilyn
Makiling, Maria Paula
Pilapil, Christine Joy

3. • Meristematic tissues
– the main function is
mitosis . The cells are
small, thin-walled, with
no central vacuole and
no specialized
features. It is located
at the growing points
of roots and stems.
Plant Cells
& Tissues

4. • Protective tissues– cover
the surface of leaves and
the living cells of roots
and stems. Its cells are
flattened with their top
and bottom surfaces
parallel. The upper and
lower epidermis of the
leaf are examples of
protective tissue
Plant Cells
& Tissues

5. • Parenchyma cells – large,
thin-walled, and usually have
large central vacuole. They
are often partially separated
from each other and are
usually stuffed with plastids.
In areas not exposed to
light, colorless plastids
predominate and food
storage is the main function.
Plant Cells
& Tissues

6. • Sclerenchyma – the walls of
these cells are very thick
and built up in a uniform
layer around the entire
margin of the cell. Often,
the cells dies after its all
wall was fully formed.
Sclerenchyma cells give
mechanical support to other
cells types.
Plant Cells
& Tissues

7. • Collenchyma cells –have
thick walls that are specially
thick at their corners. These
cells provide mechanical
support for the plant. They
are found in areas that are
growing rapidly and need to
be strengthened. The petiole
of leaves is usually
reinforced with collenchyma.
Plant Cells
& Tissues

8. • Xylem – conducts water
and dissolved minerals
from the roots to all the
other parts of the plants.
These are thick-walled
tubes that can extend
vertically through several
feet of xylem tissues. It
gives strength to a trunk.
Plant Cells
& Tissues

9. •Phloem – transport
sugars from one
part to another. It
is made of sieve
tube elements and
companion cells.
Plant Cells
& Tissues

11. Vascular Plants
Root System
Vegetative
(non-
reproductive)
Reproductive
Leaves Stems Flowers Fruits
Shoot System

13. Leaf
• is an organ of a vascular plant and is the principal lateral
appendage of the stem . The plant leaf is an organ whose shape
promotes efficient gathering of light for photosynthesis. The
form of the leaf must also be balanced against the fact that
most of the loss of water a plant might suffer is going to occur
at its leaves (transpiration). Leaves are extremely variable in
terms of their size, shape, and adornments (such as small hairs
on the face of the leaf). Although the leaves of most plants carry
out the same basic functions, there is nonetheless an amazing
variety of leaf sizes, shapes,margin types, forms of attachment,
ornamentation , and color.

14. Parts of a leaf:
apex – the tip of the blade
margin – the surrounding edge of the
blade
vein – the slender structure branching
from the midrib
base – the lower part of the blade where
midrib starts
petiole – the stalk which attaches the
blade to the stem
stipule – leaf-like structure arising from
the lower part of the petiole
midrib - the slender structure dividing
the blade into right half and left half
Leaf

15. • It is the part of the plant that holds up other
structures such as the leaves and flowers. It conducts
water and food substances through the xylem and
phloem.
Internal Features of Stem
• Apical meristem – Tissues at the tip of a stem capable
of cell division, gives rise tostem elongation.
• Epidermis – Outer layer of wax-coated cells that
provides protection and covering.
• Cortex – Primary tissues of a stem externally bound by
the epidermis and internally by the phloem.
Stem

16. Vascular bundle :
Xylem tissues – Distribute water and minerals from the
roots up through the plant. Xylem provides the
structural support in plants, becoming the “woody ”
tissue.
Cambium tissues are the single-celled layer of
meristematic (dividing) tissues that continually
divides to form phloem tissues toward the outside
and xylem tissues toward the inside. Cell division of
the cambium tissue adds width to the stem.
Phloem tissues (inner bark) – distribute sugars ( products
of photosynthesis ) throughout the plant. It is
important to understand what happens when the
phloem is blocked, as when a tree is girdled with a
tie or rope. The stem often enlarges just above the
blockage due to the sugars moving down from the
leaves for distribution throughout the plant.
Tissues below the blockage slowly starve. Roots die
back, eventually leading to death of the plant.
Pith – Center of dicot plant stems. In some plants the
pith breaks down forming a hollow stem. In older
woody plants, the pith is filled with rigid xylem
wood fiber.

17. • In woody dicot plants, the rings
grow to make a complete ring
around the stem.Xylem growth
makes the “annual rings” used to
tell a tree’s age. In woody dicot
plants,water and mineral movement
occurs in the more recent years of
xylem rings. Drought reduces the
size of the annual rings ( size of
xylem tubes ) and thus the
potential for water and nutrient
movement. Multi-year droughts,
with their corresponding reduction
in xylem size , have long-term
impacts on plant growth potential.
Monocot or Dicot Cross-section
of dicot Stem
Left: herbaceous/
Right: woody

18. • Bud – A stem's primary growing point. Buds can be either leaf buds
(vegetative) or flower buds (reproductive). These buds can be very
similar in appearance, but flower buds tend to be plumper than leaf
buds.
• Terminal bud – Bud at the tip of a stem. In many plants, auxin (a
plant hormone) released from the terminal bud suppresses
development of lateral buds, thereby focusing the growth of the
plant upward rather than outward. If the terminal bud is removed
during pruning (or natural events) the lateral buds will develop and
the stem becomes bushy.
• Lateral buds – grow from the leaf axils on the side of a stem.
• Bud scales – a modified leaf protecting and covering a bud
• Naked bud – bud without a protective bud scale
• Leaf scar – Mark left on stem where leaf was attached. Often
(External features of stem) used in woody plant identification.
External Features
of Stem

19. • Bundle scar – Marks left in the leaf scar from the vascular tissue
attachment. Used in woody plant identification.
• Lenticel – Pores that allow for gas exchange.
• Terminal bud scale scars or annual growth rings – Marks left on
stem from the terminal bud scales in previous years. Terminal bud
scale scars are an external measure of annual growth. Therefore,
they are important in assessing plant vigor.
• Node – Segment of stem where leaves and lateral buds are
attached.
• Internode – Section of a stem between two nodes.
• Bark – Protective outer tissue that develops with age. Used in
woody plant identification.
External Features
of Stem

20. Node and Internode
Terminal bud scars or annual
growth rings

21. • The type of bud is also used in plant identification
Bud Type

22. Woody Plants:
• Shoot – First year growth on a woody or herbaceous plant.
• Twig – Woody stem less than one year old.
• Branch – Woody stem more than one year old.
• Trunk – Main support stem(s) of woody plants.
• Water sprouts – Juvenile adventitious shoots arising on a
branch. Generally very rapid, upright-growth, and poorly
attached to the main limb.
• Suckers – Juvenile adventitious shoots arising from the roots,
generally rapid, uprightgrowing.
• Canes – Stems with relatively large pith and usually living for
only one to two years (roses, grapes, blackberries, and
raspberries).
Common Types
of Stems

23. Modified Stems:
• Bulb – Thickened, underground stem with fleshy
storage leaves attached at base (lilies, onions)
• Corm – Short, thickened, underground stem with
reduced scaly leaves (gladiolus)
• Crown – Compressed stem having leaves and flowers
growing above and roots beneath ( dandelion ,
strawberry plant, African violet)
• Stolon (or runner) –Horizontal, above-ground stems
often forming roots and/or plantlets at their tips or
nodes ( strawberry runners, spider plants)
• Rhizome – Horizontal, underground stem, typically
forms roots and plantlets at tips or nodes (iris, bent
grass, cannas)
Common Types
of Stems

24. Modified Stems:
• Spur – Very compressed, fruiting twig found on
some apples, pears, cherries, and ginkgo.
• Twining stems – Modified stems used for climbing.
Some twist clockwise (hops, honeysuckle); others
twist counter-clockwise (pole beans, Dutchman’s
pipe).
• Tuber – Enlarged rhizome containing stored food.
(The “eyes” of an Irish potato are the modified
buds.)
• Tuberous stem – Short, flattened, modified
storage stem (tuberous begonias, dahlias). Unlike
tubers, which have buds scattered all over,
tuberous stems only haveleaf buds on the "up"
Common Types
of Stems

26. Flower
• It is the reproductive organ of plants
classified as angiosperms. All plants have the
means and corresponding structures for
reproducing sexually. The basic function of a
flower is to produce seeds through sexual
reproduction. Seeds are the next generation,
and serve as the primary method in most
plants by which individuals of the species are
dispersed across the landscape.

27. Structure
of a Flower :
• Pistil – Central female organ of the
flower. It is generally bowling-pin
shaped and located in the center of
the flower.
• Stigma – receives pollen, typically
flattened and sticky
• Style – connective tissues between
stigma and ovary
• Ovary – contains ovules or embryo
sacs
• Ovules – unfertilized, immature seeds
• Stamen – male flower organ

28. Structure
of a Flower :
• Anthers – pollen-producing organs
• Filament – stalk supporting anthers
• Petals – Usually colorful modified leaves
that make up the “flower”, collectively
called the corolla. They may contain
perfume and nectar glands.
• Sepals – Protective leaf-like enclosures
for the flower buds, usually green,
collectivel called calyx. Sometimes highly
colored like the petal as in iris.
• Receptacle – base of the flower
• Pedicel – flower stalk of an individual
flower

29. • The number of sepals and
petals is used in plant
identification. Dicots
typically have sepals and
petals in fours , fives , or
multiples thereof.
Monocots typically have
flower parts in threes or
multiples of three.
Monocot or Dicot
Flower

30. • Complete flower is a flower containing sepals,
petals, stamens, and pistil while
• Incomplete flower lacks those parts.
• Perfect flower contains male and female parts
• while imperfect flower lacks either male or
female parts.
• Pistillate flower contains only female parts while
• staminate flower contains only male parts.
Terms Defining
Flower Parts

31. Fruit
• Fruit consists of carpels where the
ovules (seeds) develop and the
ovary wall or pericarp, which may be
fleshy (as in apples) or dry and hard
(as in an acorn). Some fruits have
seeds (mature ovules) enclosed
within the ovary (apples, peaches,
oranges, squash and cucumbers).
The peel of an orange, the pea pod,
the sunflower shell, and the skin
flesh and pit of a peach are all
derived from the pericarp. Other
fruit have seeds that are situated
on the periphery of the pericarp
(corncob,strawberry flesh).
In apples, the ovary wall becomes the fleshy
part of the fruit. Notice the small fruit
structure in the blossom.

32. Fruit Types :
• Simple fruits develop from a single ovary of a single flower and may be fleshy or
dry. Principal fleshy fruit types are the berry, in which the entire pericarp is
soft and pulpy (e.g., the grape, tomato,banana, hesperidium, and blueberry) and
the drupe, in which the outer layers may be pulpy, fibrous, or leathery and the
endocarp hardens into a pit or stone enclosing one or more seeds (e.g., the peach,
cherry, olive, coconut, and walnut).
• An aggregate fruit (e.g.,blackberry and raspberry) consists of a mass of small
drupes (drupelets), each of which developed from a separate ovary of a single
flower.
• A multiple fruit (e.g., pineapple and mulberry) develops from the ovaries of
many flowers growing in a cluster.
• Accessory fruits contain tissue derived from plant parts other than the ovary;
the strawberry is actually a number of tiny achenes (miscalled seeds) outside a
central pulpy pith that is the enlarged receptacle or base of the flower. The
core of the pineapple is also receptacle (stem) tissue. The best-known accessory
fruit is the pome (e.g., apple and pear), in which the fleshy edible portion is
swollen stem tissue and the true fruit is the central core.

33. Fruit Growth
Terms :
• Bud development – On temperate-zone woody
plants, buds typically develop midsummer of the
previous year. An exception is on summer
flowering shrubs, where the buds develop on the
current season’s wood.
• Pollination – Transfer of pollen from the male
flower to the stigma of the female flower.
• Fertilization – Union of the pollen grain from the
male flower with the egg cell in the female flower.

34. Seed
• A seed (mature ovule) is a miniature plant with a
protective cover in a suspended state of development.
Most seeds contain a built-in food supply called
endosperm (orchid is an exception). The endosperm
can be made up of proteins, carbohydrates or fats.
Seed Structure
• Seeds of monocots and dicots differ in structure and
method of emergence.

35. Monocot Seed
• Seed coat – Formed from the
wall of the embryo sack
(mother tissue)
• Endosperm – Food supply
containing 3 sets of
chromosomes (2 from the
mother and 1 from the father)
• Embryo – Immature plant
• Cotyledon – Seed leaf
• Plumule – Shoot
• Radicle – Root
Cross-section of a monocot
seed ( corn )

36. Dicot Seed
• Seed coat – Formed from
embryo sack wall and
endosperm tissue (During
development, the endosperm
stops dividing and is absorbed
into the embryonic tissues.)
• Embryo – Immature plant
• Cotyledon – Food storing seed
leaf
• Plumule – Shoot
• Hypocotyl – Stem
• Radicle – Root

38. Root System
• The roots are the beginning of the vascular
system pipeline that moves water and minerals
from the soil up to the leaves and fruits. Roots
anchor and support plants. To function, roots
must have adequate levels of soil oxygen. Soil
compaction or waterlogged soil reduces soil
oxygen levels, kills roots and lead to a shallow
root system

39. Root Structure :• Epidermis – The outer layer of cells
• Root hairs – Absorptive unicellular extensions of
epidermal cells of a root. These tiny, hair-like structures
function as the major site of water and mineral uptake.
Root hairs are extremely delicate and subject to
desiccation. Root hairs are easily destroyed in
transplanting.
• Cortex – Primary tissues of a root bound on the outside
by th epidermis and on the inside by the endodermis. In a
carrot, the cortex becomes a storage organ.
• Endodermis – A single layer of cells in a root that
separates the cortex tissues from the pericycle.
• Pericycle – A layer of cells immediately inside the
endodermis. Branch roots arise from the pericycle.

40. Vascular system :
• Phloem tissue conducts products of
photosynthesis from leaves
throughout plant including down
the roots.
• Xylem tissue conducts water and
minerals up from the roots up
through the plant.
• Zone of Maturation - Pipeline
section of the roots, conducting
water and nutrients from the root
hairs up to the stems.
• Zone of elongation –Area where
new cells are enlarging.
Cross-section of root
lateral view of root

41. Meristematic zone :
• Root tip meristem – Region of cell division that
supports root elongation, found at the root tips
just behind the root cap.
• Root cap – A thimble-shaped group of thick-
walled cells at the root tip serves as a “hardhat”
to push though soil. The root cap protects the
tender meristem tissues.

42. Types of Roots :
• Fibrous – Profusely branched roots that occupy a
large volume of shallow soil around aplant's base
(petunias, beans, peas).
• Taproot – Main, downward- growing root with
limited branching, where soils permit(carrots,
beets, radishes).
• Combination –In nursery production the taproot of
young plants (like oaks) is cut, forcing a fibrous
growth pattern. This has a significant impact on
the plant’s ability to survive transplanting.

43. Types of Roots :
• Adventitious roots - arise at an unexpected place. For
example, the brace roots on corn and the short whitish
bumps along a tomato stem are adventitious roots.
• Aerial roots - arise from above-ground stem tissues. Aerial
roots support the vine on English ivy and poison ivy.
• Lateral root – Side root
• Sinker roots - make a sharp dive into deeper soils, following
soil cracks where oxygen is available. Sinker roots are
common on some tree species.
• Storage or Tuberous root – Enlarged roots that serve as
storage organs. (Canadian thistle, morning glory, sweet
potato, dahlia).

45. Metabolism
Metabolism in plants is the collection of
interrelated biochemical reactions that
maintain plant life. A series of metabolic
processes happen in different parts of the
plants such as leaves, stems, and roots.
These processes include photosynthesis,
respiration, and nitrogen fixation.

46. The Metabolic Processes in Plants
Photosynthesis
Respiration
Nitrogen
Fixation
Transpiration

47. Photosynthesis
Photosynthesis is a series of complex
processes that convert light energy, carbon
dioxide, and water into glucose and oxygen. It
takes place in the leaves, and stems that contain
chlorophyll (the green pigments). It is divided
into two major stages, the light-reaction phase
(light-dependent phase) and the Calvin cycle
(light-independent phase).

50. Light-dependent
Reaction
The light-dependent reaction is a process that
requires the presence of light energy from the sun
and is occurring in the grana — membranous
structures within the chloroplasts. Photolysis
occurs in this stage which involves the splitting of
water molecules. This process results in the
production of O2 which is released into the
atmosphere, and organic energy molecules such as
ATP and NADPH that will join the Calvin cycle.

51. Light-independent Reaction
(The Calvin Cycle)
This reaction does not require light. This part of the
photosynthetic process is called the Calvin Cycle. With one
cycle of this reaction 3 carbon atoms are fixed or placed in a
sugar molecule. This pathway is called C-3 photosynthesis.
This is the way that most dicots or broadleaf plants make
sugars during the dark reaction. The disadvantage of this
process is that oxygen competes with CO2 for a binding site
during the dark reaction. Sometimes sugars are not formed,
but energy is still expended to complete the cycle. This is
called photorespiration.

52. The Metabolic Processes in Plants
Photosynthesis
Respiration
Nitrogen
Fixation
Transpiration

53. Respiration
Respiration in plants is the metabolic
counter process of the photosynthesis
whereas the gases (CO2 and O2) enter and
leave through their stomata. During the
process, glucose (the product of
photosynthesis) is being used to produce
carbon dioxide and water.

55. Different Stages in Respiration in Plants
Oxidative
Phosphorylation
Glycolysis
Krebs Cycle

56. Respiration in plants has different stages: glycolysis,
Krebs cycle, oxidative phosphorylation (which includes
the electron transport chain). The glucose molecule will
first enter the process of glycolysis in the cytoplasm
wherein this molecule is broken down into two pyruvate
molecules. When the oxygen is available, the 3-carbon
pyruvate molecules will be passed on to the next stages
such as Krebs cycle, oxidative phosphorylation, and
electron transport chain which occur in the powerhouse of
the cell known as mitochondria, resulting to the production
of energy in the form of ATP. When the oxygen is not
available, the pyruvate is used for alcohol fermentation.

57. The Metabolic Processes in Plants
Photosynthesis
Respiration
Nitrogen
Fixation
Transpiration

58. Nitrogen
Fixation
Nitrogen fixation is a process of
converting nitrogen from the atmosphere into
ammonia by the nitrogen-fixing bacteria
called rhizobia. This process usually happens
in the roots of legumes. The symbiotic
relationship between the nitrogen-fixing
bacteria and the legumes happens in the root
nodules.

59. Nitrogen
Fixation

60. The Metabolic Processes in Plants
Photosynthesis
Respiration
Nitrogen
Fixation
Transpiration

61. •Transpiration is
the process by
which a plant
loses water,
primarily through
leaf stomata.
Transpiration

62. That's all,
thank you.

63. Referenc
e:
http://www.mcwdn.org/Plants/Stems.html