Question

The two, more distantly related phyla among the following are

• A. Ctenophora and Platyhelminthes
• B. Annelida and Arthropoda
• C. Chordata and Echinodermata
• D. Mollusca and Echinodermata

Answer 1

Answer: (C)

Chordata and Echinodermata

Answer 2

Although there are differences in structures and forms of different animals, yet there are common fundamental features in various individuals in relation to the arrangement of cells, body symmetry, nature of coelom, patterns of different organ systems etc. These features are used as the basis of classifying animals into different taxons. Animals placed under the same taxon are more closely related to each other than to the animals placed in different taxon of the same level. In animal classification, the major phyla are Porifera, Coelenterata, Ctenophora, Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata and Chordata in sequence in which they are put in a classification system according to their affinities and resemblances. Two phyla placed side by side in the system like Ctenophora and Platyhelminthes, Annelida and Arthropoda, Mollusca and Echinodermata are more closely related than two phyla separated by one or more phyla like Echinodermata and Chordata.