Plant Structure and Function Notes

Plant Phylogeny

• Plants' phylogeny includes:
  • Charophytes (green algae).
  • Bryophytes (non-vascular plants).
  • Tracheophytes (seedless, vascular plants).
  • Gymnosperms (“naked seeds”, vascular plants).
  • Angiosperms (contained seeds, vascular plants).

Monocot vs Dicot Plants

• Comparison of monocot and dicot plants focusing on cotyledons.

Aim of the Study

• Develop the ability to analyze and understand the structure and function of plant organs.

Major Parts of a Plant and Their Functions

• Leaves: Where photosynthesis occurs.
• Seeds: Method of sexual reproduction.
• Flower: Site where reproduction occurs.
• Stem: Transports nutrients and supports the plant.
• Root: Takes in nutrients and anchors the plant.

Perfect and Complete Flower

• Pistil:
  • Stigma.
  • Style.
  • Ovary.
  • Ovule.
• Stem.
• Petal.
• Stamen.
  • Anther.
  • Filament.
• Sepal.

Tissues in Plants

• Dermal tissue: Found in the root, leaf, and stem.
• Vascular tissue: Found in the root, leaf, and stem.
• Ground tissue: Found in the root, leaf, and stem.

Dicot Root Tip - Longitudinal Section

• Regions:
  • Region of maturation.
  • Region of elongation.
  • Apical meristem (region of cell division).
• Tissues:
  • Protoderm.
  • Ground meristem.
  • Procambium.
• Root cap.

Root Cross Section

• Key Structures:
  • Epidermis.
  • Cortex.
  • Endodermis.
  • Stele.
  • Root hair.
  • Root cap.
  • Pericycle.
• Function:
  • Water and mineral absorption.
  • Casparian strip.
  • Organic molecule transport.

Monocot vs Dicots Roots

• Vascular tissue matures to form the innermost cylinder of the root.
• In dicots, the xylem forms an X shape.
• Monocots have a prominent endodermis.
• The cortex is located between the epidermis and endodermis.
• The cortex and endodermis compose the GROUND TISSUE.

Monocot / Dicot Stems

• Key Structures:
  • Epidermis.
  • Cortex.
  • Vascular bundles.
  • Pith.
  • Conjunctive tissue.