Plant Structure and Growth

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Plant Structure and Growth
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Figure 35.1 A comparison of monocots and dicots
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Figure 35.2 Morphology of a flowering plant an
overview
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3 organs of plants

• Roots anchor plant, prevent erosion
• absorb minerals and water
• store food
• Stems transport system
• store food (tubers ex potato)
• support leaves
• protect tissues
• Leaves - photosynthesis
• funnel water to roots

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Figure 35.4 Modified shoots Stolons, strawberry
(top left) rhizomes, iris (top right) tubers,
potato (bottom left) bulb, onion (bottom right)
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Figure 35.5 Simple versus compound leaves
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Figure 35.6 Modified leaves Tendrils, pea plant
(top left) spines, cacti (top right) succulent
(bottom left) brightly-colored leaves,
poinsettia (bottom right)
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Figure 35.7 The three tissue systems
Vascular transport (xylem and phloem) Dermal
outer coverings, protection, water
conservation (epidermis, cuticle)
Ground filler, packing material for
cushioning Also Can photosynthesize, store
materials, and support plant
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Figure 35.12 Locations of major meristems an
overview of plant growth
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Meristems

• Regions of active cell division
• Apical meristems at tips or apex of roots and
  buds of shoots
• for PRIMARY GROWTH
• Lateral meristems cylinders of dividing cells
  extending along length of roots and shoots
• for SECONDARY GROWTH

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Figure 35.14 Primary growth of a root
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Primary tissues of roots

• Epidermis -- dermal
• Cortex -- ground
• Stele -- vascular
• Endodermis -- ground
• Pericycle -- vascular
• Pith -- vascular
• Xylem -- vascular
• Phloem -- vascular

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Figure 35.15 Organization of primary tissues in
young roots
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Primary tissues of stems

• Epidermis -- dermal
• Cortex -- ground
• Vascular Bundle vascular
• sclerenchyma, phloem, xylem
• Pith -- ground

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Figure 35.18 Organization of primary tissues in
young stems
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Tissues of Leaves

• Cuticle
• Upper epidermis
• Palisade parenchyma
• Spongy parenchyma
• (contains veins xylem and phloem)
• Lower epidermis
• (contains guard cells)
• Cuticle

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Function of Guard Cells
Section 23-4
Guard cells
Guard cells
Inner cell wall
Inner cell wall
Stoma
Stoma Open
Stoma Closed
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Figure 35.19 Leaf anatomy
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Figure 35.22 Anatomy of a three-year-old stem
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Figure 35.23 Anatomy of a tree trunk