Chapter 2: Biological Classification
NCERT Biology | NEET-UG Preparation | Chapter Summary
Learning objective: Understand the development of biological classification, the five-kingdom system, the major characteristics of different kingdoms, and the differences between viruses, viroids, prions and lichens.
Kingdom Plantae and Kingdom Animalia
Kingdom Plantae
Plantae includes multicellular eukaryotic organisms that generally possess cellulose-containing cell walls and obtain food through photosynthesis.
- Most plants contain chlorophyll and manufacture their food through photosynthesis.
- Cells typically have a cell wall and a large central vacuole.
- Plant life cycles may include different generations, depending on the group.
Kingdom Animalia
Animalia includes multicellular eukaryotic organisms that obtain nutrients by ingestion.
- Animal cells lack cell walls.
- Animals are heterotrophic.
- Most animals show movement during at least one stage of their life cycle.
- Many have specialised tissues, organs and organ systems.
| Feature | Plantae | Animalia |
|---|---|---|
| Cell wall | Present; typically cellulose-containing | Absent |
| Nutrition | Mainly photosynthetic autotrophy | Heterotrophy by ingestion |
| Chloroplasts | Present in photosynthetic cells | Absent |
| Body organisation | Multicellular | Multicellular |
Remember: The five-kingdom classification separates fungi from plants because their nutritional strategies and cell-wall characteristics differ.
