Question

Which one of the following is the hierarchical sequence?
A. Phylum, Class, Order, Family
B. Phylum, Division, Family, Class
C. Genus, Species, Order, Family
D. Division, Order, Class, Genus

Answer 1

Hint: The system of classification which we follow currently is known as the Five Kingdom Classification and it was given by R. H. Whittaker.

Complete answer:
Under the five-kingdom classification, all living organisms are classified on the basis of their cellular makeup. The five kingdoms are –
1. Kingdom Monera
2. Kingdom Protista
3. Kingdom Fungi
4. Kingdom Plantae
5. Kingdom Animalia
The kingdom is the highest level of classification. All the organisms in a kingdom are further classified on the basis of similarities and dissimilarities from each other. The next hierarchical level is Phylum, followed by Class, Order, Family, Genus, and Species.
1. All the organisms placed in a species have the most similarities with each other. The number of similarities decreases as we go higher from species to kingdom. Therefore, the hierarchical structure for classification is as follows –Kingdom
2. Phylum / Division
3. Class
4. Order
5. Family
6. Genus
7. Species
Now, let’s see which option shows these hierarchical levels in the correct order.
In option A, hierarchical levels number 2, 3, 4, and 5 are mentioned in the exact same order as it should be. So, this option is correct.
In option B, the hierarchical level number 2, i.e., Phylum is mentioned first. After that its other name Division is mentioned. It is followed by level number 5, i.e., Family, while the intermediate levels are missed. Then, level number 3 is mentioned completely out of sequence. So, this option is incorrect.
In option C, hierarchical level number 4 is mentioned first, followed by level number 7. It is correct here. After this, level number 4 is mentioned followed by level number 5. So, this sequence is completely incorrect.
In option D, the hierarchical level number 2 is mentioned first, followed by level number 4, 3, and, 6. This sequence is also completely incorrect.

So, the correct answer is option A.

Note: There is another system of classification, known as the Three Domain System, given by Carl Woese et al.
The hierarchical levels are based on classifying organisms based on similarities and dissimilarities.