Plant Structure and Function

1
Plant Structure and Function

• 26-1
• How do plants manage to live just about
  anywhere?

2
The Structure of a Plant

• Organs?
• Roots anchor plant, absorb water and minerals
• Stems support, transport
• Leaves photosynthesis, efficiently arranged
• Flowers reproduction

3
Tissues

• Dermal Tissue
• Vascular Tissue
• Xylem water, minerals UP
• Phloem food DOWN or UP
• Ground tissue
• parenchyma (thin-walled)
• collenchyma, sclerenchyma (thick-walled)
• Meristematic Tissue

4
ROOTS - label a diagram

• Epidermis
• root hairs
• Cortex
• Vascular Cylinder
• Xylem
• Phloem
• Endodermis
• Casparian strip

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The Root Cross Section
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How Roots Work

• Osmosis
• Active transport
• minerals absorbed using cellular energy
• The Casparian Strip seals the endodermis
• water, minerals forced into and through cells

7
Plant Structure and Function

• 26-1
• How do plants manage to live just about anywhere?

8
What are the four parts of the vascular cylinder?

• Xylem
• Phloem
• Endodermis
• w/ Casparian strip
• Pericycle (meristematic region for secondary
  roots)

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Types of Roots?

• Tap Root
• Carrot
• Oak tree
• Fibrous Root
• Grass
• Maple tree

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STEMS

• Stems connect the roots that gather water and
  nutrients with the leaves that carry out
  photosynthesis

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Two types of stems - p. 589

• Monocot scattered vascular bundles
• Dicot with vascular bundles in a circle

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Label a diagram of a dicot stem

• pith
• xylem
• annual rings
• vascular cambium
• phloem
• cork cambium
• cork (bark)

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ANNUAL RINGS

• When are the xylem cells growing larger?
• Winter, spring summer or fall?
• In the moist spring.
• In the summer they grow smaller.

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This causes annual rings.

• Spring wood has larger cells than summer wood.
• The different size cell in the spring wood and
  summer wood makes an annual ring clearly visible.

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What are the four areas of cell division in a
plant?

• Root meristem
• Apical meristem
• Vascular cambium
• Cork cambium

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LEAVES - Label a diagram.

• spongy mesophyll
• air space
• vein
• xylem
• phloem

• cuticle
• epidermis
• stomata
• guard cell
• palisade mesophyll

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Fluid Transport in Plants

• How does xylem and phloem move fluids?
• Animals use a heart, but plants need other
  mechanisms.

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Xylem Transport

• Water enters roots by osmosis
• Cohesion and adhesion result in capillary action
• Evaporation of water from leaves generates
  transpiration

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Phloem Transport

• The pressure-flow hypothesis
• Active transport combines with osmosis

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References
http//www.ag.arizona.edu/pubs/garden/mg/botony/pl
antparts.html