Vegetative Structures of Plants
Six Main Parts
flower
leaves
fruit
stem
seed
roots
Leaves
0 Capture light
0 Exchange gases
0 Provide a site for
photosynthesis
0 Some leaves store food
and water
0 Some form new plants
and provide support
Photosynthesis
0 A process by which plants combine water and carbon dioxide in the
presence of chlorophyll and sunlight and produce carbohydrates and
release oxygen
0 The chemical equation for photosynthesis is:
6CO2 + 6H2O → C6H12O6 + 6O2
Why is photosynthesis important?
0 Light is the most important source of energy for living things
0 Photosynthesis converts light into nutrients that can be used by plants and
animals
Photosynthesis Reactions
0 Light Reactions
0 Produce chemical energy from light
0 Dark Reactions
0 Convert carbon dioxide into carbohy6drates
Gas Exchange Process
0 O2, CO2, and H2O are exchanged through small pores in the leaves called a
stomata
0 Each stomata is surrounded by two guard cells
0 Guard cells open during the day allowing water to transpire
0 Guard cells close at night and during dry conditions to prevent water loss
Respiration
0 Plants, like animals respire 24 hours a day.
0 During respiration, plants consume oxygen and give off carbon dioxide, just
like animals
0 Roots, stems, and leaves all use oxygen as they grown and breathe out
carbon dioxide.
0 Poor soil drainage causes roots to suffer most from short oxygen supply and
possible plant death.
True or False
Plants produce more oxygen through photosynthesis
than they consume through respirations and growth
processes.
Respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
0 Respiration is a process in which energy is generated in cells
0 In respiration, glucose (sugar) and oxygen are converted into CO2, H20, and
ATP (adenosine triphosphate)
0 Respiration takes places in the mitochondrion of both plant and animal cells
Parts of the Leaf
midrib
internode
petiole
node
stem
axillar
y bud
margin
blade
External Leaf Parts
0 Petiole
0 The stalk of the leaf that attaches it to the stem
0 Midrib
0 The main vein of vascular tissue
0 Blade
0 The photosynthetic site of the leaf
Internal Parts of the leaf
0 Cuticle
0 A LAYER OF FATTY SUBSTANCES ON THE OUTSIDE OF THE LEAF THAT
PREVENTS WATER FROM ESCAPING
0 Epidermis (Lower & Upper)
0 A layer of transparent cells that permit the passage of light to the
photosynthetic cells
0 Parenchyma
0 The photosynthetic cells of the leaf
Internal Parts of the Leaf
0 Mesophyll
0 The middle of the leaf, composed of parenchyma cells
0 DIVIDED INTO PALISADE MESOPHYLL AND SPONGY MESOPHYLL
0 Palisade Mesophyll
0 Column shaped cells near the surface where most of the photosynthesis takes
place
0 Spongy Mesophyll
0 Irregular shaped cells that underlie the palisade cells
Internal Parts of the Leaf
0 Veins
0 Vascular tissue which brings water from the roots and carries away the
products of photosynthesis
0 Stoma
0 Function in transpiration and gas exchange
0 Guard Cells
0 Regulate the opening and closing of the stomata
Stomata
0 Stomata are openings with the epidermis of the leaf
0 Functions
0 To allow air into the leaf
0 To allow water and oxygen out of the leaf
Monocot vs. Dicot
0 Monocot
0 Tap Root
0 Dicot
0 Fibrous Root
Roots
0 absorb water and
minerals
0 anchor the plant
0 Stores food
0 Propagation
Taproots
0 Advantages
0 Penetrate soil deeper
0 Obtain water from lower levels
0 Anchor the plant
0 Disadvantages
0 Difficult to remove and harvest plants
0 Do not stabilize the soil well
Fibrous Roots
0 Advantages
0 Shallower, therefore they respond more quickly to fertilization and irrigation
0 Stabilize the soil better
0 Disadvantages
0 Less drought resistant
0 Tend to get exposed during cultivation
Parts of the Root
root hairs
secondary root
primary root
root cap
Root Part Functions
0 primary root: the thickest part, grows down
0 secondary roots: not as thick as primary, grow out to the
side
0 root hairs: thin, fine roots that absorb water and
nutrients
0 root cap: on the end, protects and guides the tip
Root Types
0 Adventitious Roots
0 Come from stems of leaves instead of another root
0 Fibrous Roots
0 Structures in which the primary and lateral roots develop equally so
that there is not a definite taproot
0 Storage Roots
0 Structures like carrots and sweet potatoes which are used for foot
storage
Root Parts
0 Apical Meristem
0 region of active cell division; the growing point of the plant
0 Region of elongation
0 cells here grow longitudinally which causes the root to grow longer
0 Region of differentiation
0 the region of mature primary tissues which is an area of active water and
mineral absorption
0 Xylem
0 transports water and nutrients upward
0 Phloem
0 transports carbohydrates and sugars downward
Stem
0 Water and mineral
transport by capillary action
and cohesion to the leaves
0 Transport food to the roots
0 Gas exchange
0 Produce and support new
leaves, branches, and
flowers
Internal Parts of the Stem
0 Phloem
0 Transports sugars and carbohydrates to roots
0 Xylem
0 Transports water and nutrients from roots to rest of tree
0 Cambium
0 Lateral meristem is the growing part of the stem
Internal Parts of the STem
0 Pith
0 Occupies the central area of the stem
0 Ray
0 Cortex
0 Composed of several layers of thick-walled cells and an area
of thin-walled parenchyma cells interior to the thick-walled
External Parts of the Stem
0 Buds
0 Axillary and terminal
0 Nodes
0 Internodes
Flowers
0 where reproduction
takes place
0 flowers contain male and
female parts
0 becomes the fruit and
seeds
Fruit
0 helps seeds spread
0 birds and animals eat the
seeds or carry off the fruit
0 some seeds cling to fur
and hair
Seeds
0 become the new plant
0 are spread by birds,
animals, wind, and water
Parts of the Flower
anther style
stigma
petal pollen
filament
pistil
ovary
stamen
Flower Part Functions
0 sepals: outer section; protects developing flower
0 petals: attract insects for pollination
0 pistil: female part of the flower
0 stigma
0 style
0 ovary
0 stamen: male part of the flower
0 anther
0 filament