Question

Five kingdom system of classification suggested by R.H. Whittaker is not based on:

• A. Mode of reproduction
• B. Mode of nutrition
• C. Complexity of body organisation
• D. Presence or absence of a well-defined nucleus

Answer 1

The Correct Option is D

The five kingdom system of classification was proposed by R.H. Whittaker in 1969. This system classifies living organisms into five distinct kingdoms:

1. Monera
2. Protista
3. Fungi
4. Plantae
5. Animalia

Whittaker's classification was based on several criteria, including:

• Mode of nutrition: Classified organisms based on how they obtain their food, such as autotrophic (producing their own food) or heterotrophic (consuming organic material).
• Mode of reproduction: Considered how organisms reproduce (sexually or asexually).
• Complexity of body organization: Took into account whether organisms are unicellular or multicellular, and the complexity of their body structures.

However, the presence or absence of a well-defined nucleus (prokaryotic vs. eukaryotic nature) was not a criterion explicitly considered by Whittaker. Although it indirectly influences the classification (e.g., prokaryotes are classified under Monera), the decision was not directly based on this factor.

Therefore, the five kingdom system is not based on the presence or absence of a well-defined nucleus. This criterion is more explicitly addressed in the three-domain system proposed by Carl Woese, which classifies life into Bacteria, Archaea, and Eukaryota based on cellular organization and genetic differences.

Hence, the correct answer is: Presence or absence of a well-defined nucleus.