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Plant Structures
Original PowerPoint created by Mr. Morgan
Modified by Georgia Agriculture Education Curriculum Office
Adapted by Georgia Organics 2009
What Are primary parts of plants?LeavesStemsRootsFlowers
What are the functions of leaves?Capture lightExchange gasesProvide a site for photosynthesisSome leaves store food and waterSome form new plants and provide
support
What is photosynthesis?It is a process by which plants
combine water and carbon dioxide in the presence of chlorophyll and sunlight and produce carbohydrates and release oxygen.
Why is photosynthesis important?Light is the most important
source of energy for living things. Photosynthesis converts light into nutrients that can be used by plants and animals.
Releases oxygen
PhotosynthesisLight+6CO2+12H20-Sunlight-
> C6H1206+6O2+6H20
There are two parts of photosynthesis--the light and dark reactions.The light reactions produce
chemical energy from light.The dark reactions convert
carbon dioxide into carbohydrates.
Leaves in gas exchangeOxygen, Carbon Dioxide, and
Water exchanged from StomataPores open in day to transpire
H2O and allow gases to enterClose during dry conditions to
prevent H2O loss.
External Parts of LeavesPetiole- Stalk of leaf that
attaches to stemMidrib- Main vein of vascular
tissueBlade- Photosynthetic site of
leaf
StomataOpenings on the
epidermisallows air into leafallows H2O and oxygen
out of leaf
StemsWater and mineral transport by
capillary action and cohesion to the leaves.
Transport food to the rootsGas exchangeProduce and support new
leaves, branches, and flowers
Internal parts of stemPhloemXylemCambiumPithCortex
FunctionsPhoem-Sugar and
carbohydrates to rootsXylem- Water and nutrientsCambium- Growing part of
stem
Function Cont’Pith-Occupies the central
area of the stemCortex- Composed of
several layers of thick-walled cells
External parts of stemBudsNodesInternodes
Modified StemsRhizomes- Horizontal underground
stems(Bermuda GrassStolons- Horizontal above ground
stems(strawberries)Tubers- Greatly enlarged tip of
underground stem
Cont.Bulbs- budlike structure
consisting of a small stem (onion)
Corms- Fleshly leaves underground stems with few nodes(gladiolus)
Functions of RootsAnchor plants in soilAbsorb water and nutrientsSome store reserves for future
uses(Potato)Propagation
TaprootsAdvantagesPenetrates
deeperObtain water
from other levels
Anchor plant
DisadvantagesDifficult to
remove or harvest
do not stabilize well
FibrousAdvantagesShallower,
better for fertilization & Water
Stabilize in soil better
DisadvantageLess drought
resistantTend to get
exposed during cultivation
Primary RootsGrow down into the soil and
may branch repeatedly into lateral roots
Taproot is a primary root
Lateral RootsCalled Secondary rootsgrow horizontally away from the
primary root Some grow downward
AdventitiousCame from stems or leaves
instead of another rootProp root of corn and grapes
are examples that give support
Fibrous RootRoot structures in which the
primary and lateral roots develop equally so there is not a definite taproot.
Storage RootsAre structures such as those of
carrots and sweet potatoes which are used for food storage.
What do stems and roots have in common?
Both have xylem and phloem cells for transport.
Male flowers and their parts and functions.Stamen- has two parts- filament
and antherFilament- supports the anther
Anther- Produces pollen grains
Female parts and their functionsOvule-develops into a seedOvary- surrounds the ovule, later
becomes the fruitStyle-supports the stigmaStigma- receives the pollen grainPistil- All three female parts
together
Other parts of flowerReceptacle- enlarged part of the
flower stalk where floral part is.Sepals- outer protective parts of
budsPetals- the colored part of the
flower used to attract insects
Complete FlowerBoth have Male and Female
parts
Incomplete FlowersHave either male or female
parts but not both
MonoeciousPlants that have male and
female flower parts on separate plants
DioeciousHave both parts on the
same plant.
PollinationThe transfer of pollen from one
anther to anther stigma.Two ways- self-pollination &
Cross-pollinationBees and Wind
The End