Botany Lesson Summary

Structure of a Tree

• A tree consists of three main parts: the crown, trunk, and roots.
• The trunk has five layers:
  • Bark: The protective outer layer.
  • Cambium: A growth layer that produces new bark and xylem.
  • Heartwood: The central core that provides support.
  • Phloem: Transports nutrients from leaves to the rest of the tree.
  • Xylem: Carries water and minerals from the roots to the leaves.

Plant Classification

• Plants are categorized into two main groups:
  • Angiosperms: Flowering plants (e.g., daisies) that produce seeds enclosed in fruits.
  • Gymnosperms: Non-flowering plants (e.g., pine trees) that have exposed seeds.
• Flowering plants can be further distinguished by examining seed types and leaf vein patterns.
• Non-flowering plants such as mosses and ferns reproduce via spores rather than seeds.

Importance of Plants

• Plants are essential for life on Earth, serving critical ecological functions.
• Each plant part has specific roles:
  • Roots: Absorb water and essential nutrients from the soil.
  • Leaves: Conduct photosynthesis to produce food and oxygen.
  • Flowers/Fruits: Facilitate reproduction and seed dispersal.
• Humans rely on plants not only for food but also for oxygen production.