Vegetative Structures of

Plants

leavesflower

stem

rootsseed

fruit

Six Main Parts

Leaves0Capture light0Exchange gases0Provide a site for photosynthesis

0Some leaves store food and water

0Some form new plants and provide support

Photosynthesis

0A process by which plants combine water and carbon dioxide in the presence of chlorophyll and sunlight and produce carbohydrates and release oxygen

0The chemical equation for photosynthesis is:

6CO2 + 6H2O → C6H12O6 + 6O2

Why is photosynthesis important?

0Light is the most important source of energy for living things

0Photosynthesis converts light into nutrients that can be used by plants and animals

Photosynthesis Reactions

0Light Reactions0 Produce chemical energy from light

0Dark Reactions0 Convert carbon dioxide into carbohy6drates

Gas Exchange Process

0O2, CO2, and H2O are exchanged through small pores in the leaves called a stomata

0Each stomata is surrounded by two guard cells

0Guard cells open during the day allowing water to transpire

0Guard cells close at night and during dry conditions to prevent water loss

Respiration

0Plants, like animals respire 24 hours a day.

0During respiration, plants consume oxygen and give off carbon dioxide, just like animals

0Roots, stems, and leaves all use oxygen as they grown and breathe out carbon dioxide.

0Poor 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

0Respiration is a process in which energy is generated in cells

0In respiration, glucose (sugar) and oxygen are converted into CO2, H20, and ATP (adenosine triphosphate)

0Respiration takes places in the mitochondrion of both plant and animal cells

Parts of the Leaf

petiole

blademargi

n

midrib

axillary bud

stem

internode

node

External Leaf Parts

0Petiole0 The stalk of the leaf that attaches it to the stem

0Midrib0 The main vein of vascular tissue

0Blade0 The photosynthetic site of the leaf

Internal Parts of the leaf

0Cuticle0 A LAYER OF FATTY SUBSTANCES ON THE

OUTSIDE OF THE LEAF THAT PREVENTS WATER FROM ESCAPING

0Epidermis (Lower & Upper)0 A layer of transparent cells that permit the

passage of light to the photosynthetic cells

0Parenchyma0 The photosynthetic cells of the leaf

Internal Parts of the Leaf

0Mesophyll0 The middle of the leaf, composed of parenchyma

cells0 DIVIDED INTO PALISADE MESOPHYLL AND SPONGY

MESOPHYLL

0Palisade Mesophyll0 Column shaped cells near the surface where most

of the photosynthesis takes place

0Spongy Mesophyll0 Irregular shaped cells that underlie the palisade

cells

Internal Parts of the Leaf

0Veins0 Vascular tissue which brings water from the

roots and carries away the products of photosynthesis

0Stoma0 Function in transpiration and gas exchange

0Guard Cells0 Regulate the opening and closing of the

stomata

Stomata

0Stomata are openings with the epidermis of the leaf

0Functions0 To allow air into the leaf0 To allow water and oxygen out of the leaf

Monocot vs. Dicot

0Monocot0 Tap Root

0Dicot0 Fibrous Root

Roots0absorb water and minerals

0anchor the plant

0Stores food0Propagation

Taproots

0Advantages0 Penetrate soil deeper 0 Obtain water from lower levels0 Anchor the plant

0Disadvantages0 Difficult to remove and harvest plants0 Do not stabilize the soil well

Fibrous Roots

0Advantages0 Shallower, therefore they respond more quickly

to fertilization and irrigation0 Stabilize the soil better

0Disadvantages0 Less drought resistant0 Tend to get exposed during cultivation

Parts of the Root

primary root

secondary root

root cap

root hairs

Root Part Functions

0primary root: the thickest part, grows down

0secondary roots: not as thick as primary, grow out to the side

0root hairs: thin, fine roots that absorb water and nutrients

0root cap: on the end, protects and guides the tip

Root Types

0Adventitious Roots0Come from stems of leaves instead of another

root

0Fibrous Roots0Structures in which the primary and lateral

roots develop equally so that there is not a definite taproot

0Storage Roots0Structures like carrots and sweet potatoes

which are used for foot storage

Root Parts0 Apical Meristem

0 region of active cell division; the growing point of the plant

0 Region of elongation0 cells here grow longitudinally which causes the root

to grow longer0 Region of differentiation

0 the region of mature primary tissues which is an area of active water and mineral absorption

0 Xylem0 transports water and nutrients upward

0 Phloem0 transports carbohydrates and sugars downward

Stem0Water and mineral transport by capillary action and cohesion to the leaves

0Transport food to the roots

0Gas exchange0Produce and support new leaves, branches, and flowers

Internal Parts of the Stem

0Phloem0Transports sugars and carbohydrates to roots

0Xylem0Transports water and nutrients from roots to rest of tree

0Cambium0Lateral meristem is the growing part of the stem

Internal Parts of the STem

0Pith0Occupies the central area of the stem

0Ray0Cortex

0Composed 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

0Buds0Axillary and terminal

0Nodes

0Internodes

Flowers0where reproduction takes place

0flowers contain male and female parts

0becomes the fruit and seeds

Fruit0helps seeds spread

0birds and animals eat the seeds or carry off the fruit

0some seeds cling to fur and hair

Seeds0become the new plant

0are spread by birds, animals, wind, and water

Parts of the Flowerstyle

stigma

pistil

stamen

anther

filament

ovary

petalpollen

Flower Part Functions0sepals: outer section; protects developing flower

0petals: attract insects for pollination0pistil: female part of the flower

0stigma0style0ovary

0stamen: male part of the flower0anther0filament