Biological classification is the process of grouping organisms based on similarities and differences.
R.H. Whittaker (1969) proposed the Five Kingdom Classification, which is widely accepted today.
🏷 Five Kingdom Classification
1. Monera
Prokaryotic, unicellular organisms
Cell wall made of peptidoglycan
Reproduce asexually by fission
Examples: Bacteria, Cyanobacteria
2. Protista
Unicellular eukaryotes
True nucleus & membrane-bound organelles present
Reproduce sexually & asexually
Examples: Amoeba, Euglena, Paramecium
3. Fungi
Non-green, heterotrophic, cell wall of chitin
Reproduce by spores
Can be saprophytic or parasitic
Examples: Yeast, Mucor, Mushrooms
4. Plantae
Multicellular, photosynthetic eukaryotes
Cell wall made of cellulose
Examples: Algae, Ferns, Flowering Plants
5. Animalia
Multicellular, heterotrophic, ingestive eukaryotes
Lack cell wall
Examples: Insects, Humans
🌱 Special Mentions
Lichens: Symbiotic association of algae (photosynthesis) and fungi (protection)
Viruses: Acellular, contain DNA/RNA, can reproduce only inside a host cell
Viroids: Infectious RNA particles without protein coat
🎯 Why It’s Important
Forms the foundation for understanding taxonomy, diversity, and evolution
Many NEET questions are based on key features of each kingdom, examples, and exceptions
📝 Assignment
Q1: Write two differences between Monera and Protista.
Q2: Why are viruses considered at the borderline of living and non-living?
Keywords: Biological Classification, Five Kingdom Classification, Monera, Protista, Fungi, Lichens, Viruses, Viroids, Class 11 Biology, NEET Preparation
