Five kingdom system of classification is mainly based on

Options

A. Mode of nutrition
B. Complexity of body organisation
C. Ecological role
D. Complexity of cell structure

Answer

**Step-by-Step Text Solution:**

1. **Introduction to the Five Kingdom System**: The Five Kingdom system of classification was proposed by scientist Robert Whittaker in 1969. This system categorizes all living organisms into five distinct kingdoms.

2. **The Five Kingdoms**: The five kingdoms in this classification system are:
- Kingdom Monera (bacteria and cyanobacteria)
- Kingdom Protista (unicellular eukaryotes)
- Kingdom Fungi (fungi)
- Kingdom Plantae (plants)
- Kingdom Animalia (animals)

3. **Basis of Classification**: The Five Kingdom system is primarily based on several characteristics, including:
- Mode of nutrition
- Thallus organization
- Cell structure
- Phylogenetic relationships
- Reproductive methods

4. **Main Characteristic**: Among these characteristics, the main basis for the classification is the **mode of nutrition**. This refers to how organisms obtain their food.

5. **Modes of Nutrition in Each Kingdom**:
- **Monera**: Organisms can be photoautotrophic, heterotrophic, or chemoautotrophic.
- **Protista**: Organisms can be heterotrophic or phototrophic.
- **Fungi**: All fungi are heterotrophic.
- **Plantae**: Organisms are primarily phototrophic, using photosynthesis to produce their own food.
- **Animalia**: Organisms are heterotrophic and depend on other organisms for their food.

6. **Conclusion**: Therefore, the Five Kingdom system of classification is mainly based on the mode of nutrition of the organisms.

**Final Answer**: The Five Kingdom system of classification is mainly based on the mode of nutrition.

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