Transcript Roots, Stems, Leaves, Tissues

Roots, Stems, Leaves, Tissues
BSC 2011L
Review of difference between
monocots and dicots
Organization of Flowering Plants
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3 vegetative organs that don’t have to do with
reproduction:
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Root – anchor the plant, and absorb water and minerals
Stem – supports leaves
Leaves – carry on photosynthesis
3 major tissues of vegetative organs:
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Dermal tissue
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Ground tissues
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Outer protective coating of organ
Interior of plant organ
Vascular tissue
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Xylem (transports water) and phloem (transports sugars)
Transports, supports
Ground Tissue
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3 cell types according to cell wall structure
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Parenchyma
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Large vacuoles
Important roles:
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Collenchyma
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Photosynthesis in leaves
Storage of proteins in fruits
Storage of starch in roots
Generally elongated
Provide support to leaf petioles, nonwoody stems, growing
organs
Sclerenchyma
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Thickened cell walls for support
Undergo programmed cell death often and offer support then (in
wood and bark)
Growth
 Primary
Growth
 Increases
 Secondary
length of plant
Growth
 Increases
girth of plant
Growth - Apical Meristem
 Located
at terminal end of stem, branches, root
tip
 Continuous growth
Growth – Lateral Meristem
 The
roots and stems of some Eudicots develop
secondary plant body – tissues referred to as
wood and bark

2 Lateral Meristems
 Vascular
Cambium – supplies cells of secondary
xylem and phloem which eventually become wood
and bark
 Cork cambium – waxy protective cells that become
bark
Root System
 Eudicot
Root
 Monocot
Root
Roots
 Note
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location of:
Root cap
Zone of cell division
Zone of elongation
Zone of maturation
Root Diversity
 Types
of roots
 Taproots
– main root is larger and often serves as
food storage
 Fibrous roots – all of the roots approximately same
size
Stems
 Monocots
 Usually
herbaceous (non-woody)
 Dicots
 Some
are herbaceous
 Trees - woody
Stems
 Dicot
 Monocot
Stem Diversity
 Other
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examples:
Rhizomes – horizontal
underground stems that
can give rise to new
shoots
 Bamboo
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Bulbs – stems with many
fleshy layers of leaves
that store nutrients
 Lilies,
onions
Anatomy of woody stems – only
in dicots
 Primary
growth
 Apical
 Secondary
meristem within termnial bud is active
growth
 Vascular
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
cambium is active
Produces new xylem and phloem each year
Build-up of this every year is called wood
Woody Stems
Leaves
Dicot
Monocot
Leaves
Petiole