Ch' 31 Plant Structure

1
Ch. 31 Plant Structure Function

• Groups of cells that perform a common function
  are called?
• Tissue
• Cells tissues organs systems organisms
• Plants are divided into three main groups of
  tissues
• 1. Ground tissue
• 2. Vascular tissue
• 3. Dermal tissue

2
Ground tissue

• Ground tissue contains three main kinds of cells.
• 1. Parenchyma most common tissue. Large, thin
  walled cells for storage mainly, which is helpful
  in photosynthesis.
• 2. Sclerenchyma strong rigid cells.
  Strengthens and supports the plant.
• 3. Collenchyma very flexible cells. Not as
  rigid as sclerenchyma.

3
Vascular Tissue

• Xylem ? Water Transport
• 1. Vessel elements these are large cells that
  transport most of the water in a cell. They are
  dead cells why are they dead?
• 2. Tracheids long, thick walls that are tapered
  at the ends. Conifers contain mainly tracheids
  instead of vessel elements.

4

• Phloem ? Food Transport
• 1. Sieve tube members main cell in food
  transportation.
• 2. Companion cells believed to help the
  movement of food through the sieve tube members.

5
Dermal tissue

• Dermal tissue is outside protective cells
• 1. Epidermis outer layer of cells covered with
  a cuticle if on land. 
• Leaf Picture pg.617
• There are 3 regions that stand out epidermis
  (dermal , mesophyll (ground tissue), and vascular
  bundles (vascular tissue).
• Most photosynthesis takes place in the mesophyll
  region. This region contains chloroplasts, which
  we will talk about more specifically.

6
Primary Secondary Growth

• Primary growth occurs in both herbaceous and
  woody plants. This is growth in length.
• Secondary growth occurs in woody plants. This is
  growth in width.
• The meristem is where cell growth or cell
  division occurs in plants. 2 types of meristems
  in plants.
• 1. Apical Meristem produces growth in length.
• Found at the tip of stems and roots.
• 2. Lateral Meristem produces growth in width.
• Found in the stem.

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• Annual plants live for only a year or less.
• Most are herbaceous (soft tissues no woody
  tissue).
• Their seeds may grow new plants the next year
• Examples???
• Perennials live for several years producing
  seeds each year
• Dormant in the winter most have woody tissues.
  Examples???

8
Types of Roots

• 1. Fibrous most common. Mainly weeds.
• 2. Tap largest root. Ex. Carrot
• 3. Prop starts above ground, then extends into
  the soil. Ex. Corn.
• 4. Adventitious totally above ground.
• Ex. Poison ivy
• Parts of a root Primary root, lateral roots,
  root hairs.
• Root hairs do all of the absorption.

9
Stems

• If I drove a nail into a tree 3 feet high into
  the tree, how high up the tree will the steak be
  20 years from then? Why?
• Parts of a stem
• 1. Pith center portion for storage.
• 2. Dermis
• 3. Xylem Phloem ? Annual rings

10
Leaf Structure

• The leaf is made up of blade petiole. Blade
  is the specific portion of the plants
  photosynthesis process.
• Other external features of a leaf include the
  following. 1.Cuticle waxy protective covering
  to protect against desiccation.
• 2. Stomata are the openings in the cuticle to
  allow gas exchange (CO2).
• 3. Guard Cells make up the stomata what opens
  and closes it.
• Internal Features
• 1. Mesophyll contain chloroplasts for
  photosynthesis.
• 2. Vascular bundle (veins) Xylem Phloem

11
Compound Simple Leaves

• Simple leaves 1 blade per leaf
• 1. Parallel venation
• 2. Pinnate venation
• 3. Palmate venation
• Compound leaves 2 or more blades per leaf.
• 1. Pinnately compound
• 2. Palmately compound

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