Two kingdom classification system used for a long time was inadequate, so a need was felt for including besides gross morphology, other characteristics also. What were these characters which resulted in formation of five kingdom classification system ?
(a) Cell structure
(b) Mode of nutrition
(c) Reproduction
Evolutionary relationship

Options

A. a & b
B. a, b & c
C. a, c & d
D. a, b, c & d

Answer

To answer the question regarding the characteristics that led to the formation of the five kingdom classification system, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding the Two Kingdom System**:
- The two kingdom classification system, proposed by Carl Linnaeus, categorized all living organisms into two groups: Plantae (plants) and Animalia (animals).
- This system was limited as it did not account for the vast diversity of life, particularly the differences between prokaryotic and eukaryotic organisms.

2. **Identifying the Need for a New Classification**:
- The inadequacies of the two kingdom system prompted scientists to look for a more comprehensive classification system that could better reflect the diversity of life forms.

3. **Introduction of the Five Kingdom Classification**:
- The five kingdom classification system, proposed by Robert Whittaker in 1969, includes Monera, Protista, Fungi, Plantae, and Animalia. This system is based on several key characteristics.

4. **Key Characteristics for Classification**:
- **Cell Structure**: Differentiation between prokaryotic (Monera) and eukaryotic organisms (Protista, Fungi, Plantae, Animalia).
- **Mode of Nutrition**: Organisms can be classified based on whether they are autotrophic (producing their own food) or heterotrophic (obtaining food from other sources).
- **Reproduction**: The classification also considers the modes of reproduction, which can be sexual or asexual.
- **Evolutionary Relationships**: Phylogenetic relationships help in understanding the evolutionary lineage and connections between different organisms.

5. **Conclusion**:
- The five kingdom classification system arose from the need to incorporate these various characteristics to provide a more accurate representation of the diversity of life. Therefore, the correct answer includes all the mentioned characteristics: cell structure, mode of nutrition, reproduction, and evolutionary relationships.

### Final Answer:
The characters that resulted in the formation of the five kingdom classification system are:
- (a) Cell structure
- (b) Mode of nutrition
- (c) Reproduction
- (d) Evolutionary relationship