Introductory Botany

Report
White Oak, Illinois State Tree
Rounded lobes & Acorns
Chapter 5 Notes – Pages 90 - 107
White oak trees
have bark that is
off-whitish to ashy
gray in color. It
can be very scaly
and platelike.
Older trees often
have patches of
nearly smooth
bark.
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Read Page 90
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Today, we are going to learn about
 Plant Body Structure
 Plant Life Spans
 Ground Tissue System
 Vascular System Tissues
 Dermal Tissue System
 Plant Growth
 Primary & Secondary growth
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Plant Body Structure
 All plants have the same basic body plan
 Plant body is organized into 2 Systems
 Root System (underground portion)


Tap Root
Branch Roots
 Shoot System (aerial portion)



Stem
Leaves
Flowers & Fruits *only in flowering plants*
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Plant Organs
 Roots
 Stems
 Leaves
 Flower Parts
 Fruits
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Figure 5-1
Developing fruit
Nodes (areas of leaf and
axillary bud attachment
Flower
Shoot
system
Axillary bud
Internode (area between
adjacent nodes)
Petiole Blade
Stem
Leaf
Rosette of
basal leaves
Root
system
Taproot
Branch roots
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Plants grow below & above ground
 Plants need resources from both environments
 Below ground





Dark
Moist
Nutrients / Dissolved minerals
Roots anchor the plant to the ground
Absorbs Water
 Above ground


Sunlight
Carbon Dioxide
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2 Different types of Plant Body
 Herbaceous Plants
 Do not develop persistent woody parts above ground
 Typically green exterior
 Die after growing season
 Woody Plants
 Develop persistent woody parts above ground
 Persist after growing season
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Plant Life Spans
 Annuals
 Herbaceous plants that grow, reproduce, & die in 1 year or
season
 Examples: Corn, sunflowers, most food garden plants
 Biennials
 Herbaceous plants that take 2 years to complete their life
cycles
 Examples: Carrots, cabbage, celery, & parsley
 Perennials
 Woody or herbaceous plants that live for more than 2 years
 Aerial shoots of herbaceous perennials die each winter
 Grow back in Spring
 Examples: All trees, rhubarb, onions, asparagus, iris
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Cells & Tissues of the Plant Body
 The cell is the basic structural and functional unit of
plants
 Plant cells are organized into tissues
 Tissues are groups of cells that form a structural and
functional unit
 Simple tissues – 1 kind of cell
 Complex tissues – 2 or more kinds of cells
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3 Plant
Tissue
Systems
Tissues are organized into 3 tissue systems
Ground Tissue System
1.


Most of the plant body
Functions include photosynthesis, storage, structural support
Vascular tissue system (think of veins)
2.



The plumbing system of the plant
Extends throughout the plant body
Conducts water, dissolved minerals, and food (dissolved
sugar)
Dermal Tissue System
3.


Strengthens & Supports the plant
This system covers the plant body (like skin)
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Tissue Systems throughout the
plant
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1. Composed
Ground
System
Tissue
of 3 Simple Tissues
Parenchyma
1.




Cells have thin primary cell walls
Unspecialized – Can differentiate into other kinds of cells
Functions: Photosynthesis, storage, & secretion
Most common type of cell & tissue in plants
Collenchyma
2.

Cells have unevenly thickened primary cell walls
Sclerenchyma “Sclero” means “Hard”
3.


Cells have both primary cell walls & thick secondary walls
Provides support to plant body
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Parenchyma Cells
Thin Primary Cell Walls
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Collenchyma Cells
Thick Cell Walls
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Sclerenchyma Cells
Have both primary and secondary cell walls
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2. Composed
Vascular
Tissue
System
of 2 Complex Tissues
 Xylem
 Conducts water and dissolved minerals
 Transfers from Roots  stem & leaves
 Composed of 2 types of cells
 Tracheids – chief water conducting cells
 Vessel Elements – have holes in end cell walls
 Phloem
 Conducts food throughout the body
 Composed of 4 types of cells
 Sieve-tube elements – highly specialized cells
 Companion cells
 Phloem fibers (long tapered cells)
 Phloem parenchyma cells
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3. Dermal Tissue Systems
 Composed of 2 Complex Tissues
 Epidermis
 Periderm
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Epidermis
 Outermost layer of herbaceous plant, usually one cell
thick
 Covers the primary plant body (leaves, young stems
and roots)
 Prevent Water Loss
 Secretes a waxy cuticle
 Stomata regulates gas exchange using guard cells
 Composed of 2 types of cells
 Guard cells
 Trichomes
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Stomata
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Periderm
 Replaces epidermis in woody plants
 Forms the protective, outer bark
 Outermost layer of cells covering a woody stem or root
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Periderm
Exterior
environment
Remnants
of epidermis
Cork cells
Cork
cambium
Cork
parenchyma
Periderm
Geranium
Cortex
(interior of stem)
Fig. 5-10, p.22103
Table 5-2a, p. 104
Table 5-2b, p. 104
Primary Growth
 Increase in stem and root length
 Result of activity of apical meristems at the tips of
roots and at the buds of stems
 Apical Meristem

An area of cell division at the tip of a stem or root in a plant;
produces primary tissues
 Bud

A dormant embryonic shoot that eventually develops into an
apical meristem
Root Tip
Stem Tip
Secondary Growth
 Increase in stem and root girth
 Secondary growth is localized, typically as long
cylinders of active growth throughout the lengths of
older stems and roots
 Lateral Meristem
 An area of cell division on the side of a vascular plant
 Gives rise to secondary tissues
 2 Lateral Meristems

Vascular Cambium

Cork Cambium
Lateral Meristems and Secondary
Growth

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