Plant Kingdom

Introduction

• Purpose of the lecture: To understand the Plant Kingdom in detail.
• Previous curriculum: Cytology, Systematics (Living World, Biological Classification).
• Objective: To comprehend the Plant Kingdom and its subdivisions.

Key Points

1. Characteristics of Plants

• Autophototrophic, meaning making their own food through photosynthesis.
• Cell Wall: Contains cellulose.
• Mostly multicellular and eukaryotic.

2. Classification of Angiosperms

• Artificial System:

  • Given by Carolus Linnaeus.
  • Based on superficial morphological characters.
  • Limited as vegetative characters are affected by the environment.

• Natural System:

  • Given by Bentham and Hooker.
  • Based on natural affinities.

• Phylogenetic System:

  • Given by Engler and Prantl.
  • Based on evolutionary relationships.
  • Currently the most accepted system.

3. Algae

Main Characteristics:

• The simplest plants, mostly aquatic.
• Primarily fix CO2 through photosynthesis.
• An important part of the food chain.
• Produce hydrocolloids like algin, carrageenan.

Classification:

• Green Algae (Chlorophyceae):

  • Chlorophyll a and b, storage food: starch, oil droplets.

• Brown Algae (Phaeophyceae):

  • Chlorophyll a and c, fucoxanthin, storage food: mannitol, laminarin.

• Red Algae (Rhodophyceae):

  • Phycoerythrin, storage food: floridean starch.

4. Bryophytes

• Amphibians of the Plant Kingdom.
• Gametophytic body dominant.
• Examples: Liverworts, mosses.

5. Pteridophytes

• Presence of true vascular tissues.
• Dominant sporophyte.
• Examples: Selaginella, Equisetum.

6. Gymnosperms

• Naked seeds, tall trees like Sequoia.
• Examples like Pinus and Cycas.

Conclusion

• Importance of the Plant Kingdom: Contribution to the ecosystem.
• Next steps for research and study.

With these notes, students will be able to understand the various subdivisions of the Plant Kingdom and their characteristics. This study guide will aid in exam preparation.