Plantae

Key Notes:

Introduction to Kingdom Plantae

  • Plantae is one of the five kingdoms in biological classification.
  • Includes multicellular, eukaryotic, autotrophic organisms that produce their own food through photosynthesis.
  • Common examples: trees, shrubs, herbs, mosses, and ferns.

Characteristics of Plantae

  • Cell Structure: Cells have a rigid cell wall made of cellulose.
  • Chlorophyll: Contain chloroplasts with chlorophyll for photosynthesis.
  • Reproduction: Both sexual and asexual reproduction methods.
  • Nutrition: Autotrophic (synthesize food using sunlight, water, and carbon dioxide).

Classification of Plantae

Plantae is divided into various groups based on structure, vascular system, and reproduction:

  • Thallophyta:
    • Simplest plants, body not differentiated into roots, stems, and leaves.
    • Example: Algae.
  • Bryophyta:
    • Non-vascular plants, require water for reproduction.
    • Examples: Mosses, liverworts.
  • Pteridophyta:
    • Vascular plants without seeds.
    • Examples: Ferns.
  • Gymnosperms:
    • Vascular plants with naked seeds.
    • Examples: Pine, cycas.
  • Angiosperms:
    • Vascular plants with seeds enclosed in fruits (flowering plants).
    • Examples: Mango tree, sunflower.

Vascular System

  • Consists of xylem (transports water and minerals) and phloem (transports food).
  • Found in higher plants (Pteridophyta, Gymnosperms, Angiosperms).

Significance of Plantae

  • Primary producers in the ecosystem, forming the base of the food chain.
  • Produce oxygen as a by-product of photosynthesis.
  • Provide food, shelter, and raw materials for humans and animals.

Adaptations

  • Adapted to diverse habitats: aquatic (e.g., algae), terrestrial (e.g., trees), and extreme environments (e.g., cacti in deserts).

Reproductive Structures

  • Spore-producing plants: Thallophyta, Bryophyta, and Pteridophyta.
  • Seed-producing plants: Gymnosperms and Angiosperms.
  • Flowers are the reproductive organs in Angiosperms.

Economic Importance

  • Food crops (wheat, rice), medicinal plants, timber, and ornamental plants.
  • Source of industrial raw materials like cotton and jute.

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