In which kingdom did Whittaker place Chlamydomonas and Chlorella? What was their earlier position in the two-kingdom system?
GeneralClass 12AllAnswered 27 Mar 2026
Answer
Whittaker's Classification (1969):
- Kingdom: Protista
- Rationale: Unicellular eukaryotic organisms with simple organization
Earlier Position (Two-Kingdom System):
- Kingdom: Plantae
- Group: Algae (Thallophyta)
- Reason: Presence of cell wall and photosynthetic capability
Comparative Analysis:
|
Organism |
Two-Kingdom |
Five-Kingdom |
Key Features |
|
Chlamydomonas |
Plantae (Algae) |
Protista |
Unicellular, flagellated, photosynthetic, eyespot |
|
Chlorella |
Plantae (Algae) |
Protista |
Unicellular, non-motile, spherical, chloroplast |
Whittaker's Logic: Despite having cell walls and chlorophyll (plant-like features), these organisms are:
- Unicellular (not tissue-level organization)
- Simple eukaryotes (lack differentiation)
- Evolutionarily distinct from multicellular plants
Common Exam Pitfall: Students often assume all photosynthetic organisms belong to Plantae. Remember: nutritional mode alone doesn't determine kingdom classification.
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