Unit 3 Lesson 8 Leaf Structures and Functions

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Unit 3Lesson 8Leaf Structures and Functions
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Functions of the Leaf

• The most important function of the leaf is to
  manufacture food for the plant by using light
  energy
• Photosynthesis
• Phototropism

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Internal Leaf Structure

• Stomata
• Guard Cells
• Cuticle
• Upper Epidermis
• Lower Epidermis

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Internal Leaf Structure

• Palisade Mesophyll
• Vascular Bundle
• Xylem
• Phloem
• Spongy Mesophyll

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External Leaf Components

• Define or list the functions of each of the
  following external leaf components
• Midrib
• Lamina
• Petiole
• Stipule
• Lamina
• Ligule
• Auricle
• Sheath

SIMPLE LEAF
GRASS LEAF
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Types of Veins Found in Leaves

• Parallel-Veined Leaves Grasses, have veins that
  run parallel to each other and are joined by
  inconspicuous tiny veins.
• Net-like veined leaves a few prominent veins
  with a large number of minor veins. Built like
  spider webs, out from midrib. Includes all crops
  other than grasses.

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LEAF ARRANGEMENTS
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Leaf Arrangments

• Palmately Compound Blade divided into leaflets,
  , leaflets coming from one point and only
  dividing once.
• Pinnately Compound Blade divided into leaflets,
  leaflets coming from more than one point,
  dividing again.
• Bipinnately Compound Blade divided inot
  leaflets, leaflets coming from more than one
  point, dividing two more times.
• Alternate
• Whorled
• Opposite

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Internal Leaf Structure Assignment

• In order to help you understand the internal
  structure of a leaf, you are going to create your
  own leaf. The following are some guidelines.
  Presentations will take place on _______.

• Leaf must be in actual leaf shape.
• Inner leaf structure must be made of at least
  five edible components (Twizzlers, rice, etc.)
• Leaf must include the following Cuticle,
  upper epidermis, palisade mesophyll, vascular
  bundle, xylem, phloem, lower epidermis, spongy
  mesophyll, guard cells, and stomata.
• Must work with a partner.
• All presentations must be completed on assigned
  date.
• Presentations will be graded on
• Creativity
• Accuracy
• Description of structure functions
• Inclusion of all structures

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Can You Identify These Leaves?
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