PLANT STRUCTURE AND FUNCTION D Jones. Plant Cell Types parenchyma –metabolism –storage...
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Transcript of PLANT STRUCTURE AND FUNCTION D Jones. Plant Cell Types parenchyma –metabolism –storage...
PLANT STRUCTURE AND FUNCTION
D Jones
Plant Cell Types parenchyma
– metabolism– storage– contain plastids that store
store starch – support with growth
sclerenchyma– support without growth– two forms
fibers (flax and hemp) sclereids (nutshells)
Xylem water conducting
dead at maturity– tracheids
• long, thin, tapered ends– vessel elements
• wider, shorter, thin walled, less tapered
Phloem food conducting live at maturity
– sieve-tube members• Have sieve plates
– companion cells
Tissue Systems dermal
– epidermis tightly packed cells cover and protect
vascular– xylem & phloem
transport & support
ground– mostly parenchyma
photosynthesis, storage & support
– collenchyma– sclerenchyma
Plant Systems roots Stems leaves flowers & seeds
Functions of Roots absorb water and nutrients anchor plants conduct water and nutrients store food
Types of Roots fibrous roots
– mat of thread-like roots– just below soil surface– found in monocots
tap roots– one long root– deep into soil– found in dicots
Root Cross Section
Monocot
Dicot
epidermiscortex
endodermis xylem
pericycle
xylem
phloem
cortex
Tissue Characteristics & Functions
Tissue Characteristics Function
Cortex Cellular spaces for aeration
Stores starch
endodermis Tightly packed produce suberin(creates water barrier called casparian strip
Control movement of water into center of root and prevent outward movement
Root hairs give surface area for absorption
Functions of Stems transport materials support storage
Types of Stems Herbaceous
– in annuals– green (photosynthesize)– pliable
Woody– in perennials– have bark– inflexible
Stem Cross Sectionsmonocot
dicot
phloem
xylem
vessel element (xylem)air spacephloem
Tissue functions epidermis – produces waxy cuticle of
cutin to protect from water loss cortex – ground tissue containing
chloroplasts vascular cylinder – xylem, phloem and
pith
Woody Stemperiderm
cork cambium
cortexphloem
xylem
vascular cambium
pith
Tissue functions
vascular cambium – produces new xylem and phloem
periderm (bark or cork)– protects from water loss
cork cambium – produces periderm Sapwood – outermost water-conducting
xylem Heartwood – innermost supporting xylem
Leaf Functions photosynthesis – food production
Functions of Leaves photosynthesis
Types of Leaves Simple
compound– Pinnate
– palmate
Leaf Cross Section
Tissue Functions epidermis – covered by waxy cuticle of cutin
that limits water loss palisade mesophyll – specialized for
photosynthesis – tightly packed spongy mesophyll – air spaces allow gas
exchange guard cells – open and close stomata to
allow gas exchange and limit water loss vascular bundles – transport of water and
food
Stomata Functioning guard cells have thicker cell walls near
the stomata when water moves into guard cells
they expand and open when water moves out the guard cells
close
Factors that Affect Stomata
temperature – stomata close limiting water loss when the temperature is high
CO2 concentration – stomata open when CO2 is low allowing photosynthesis
day/night – stomata open during the day and close at night
Flowers and Seeds reproduction
Flower structure
Functions of Flower Parts petals – attract birds and insects sepals – protect flower buds stamen – male structures that produce
pollen pistil – female structures tha produce
ovules
Seeds
Tissue Functions seed coat - protection Endosperm - storage Cotyledon - storage epicotyl – becomes shoot tip hypocotyl – becomes shoot radical – becomes root
Monocot /Dicot Comparison