Chapter 25, Problem 25A

Summary Introduction

Introduction :

The phylogenetic tree can be defined as the linear representation of the evolutionary relationship between the organism. It is used to determine the similarity and the difference between the evolution of the organism.

Answer to Problem 25A

Correct answer :

Option (B).

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) Coelom. The mollusks belong to the group coelomates. The roundworms and other pseudocoelomates do not have this characteristics. Hence, the correct answer is option (C).

Explanation for incorrect answer :

Option (A) pseudocoelom. The phylogenetic tree shows that mollusks emerged after evolution of coelom. Hence, it is an incorrect answer.

Option (C) solid bodies. There is no classification of the organism on the basis of solid body in this phylogenetic tree. Hence, it is an incorrect answer.

Option (D) shells. There is no classification of the organism on the basis of presence or absence of shells in this phylogenetic tree. Hence, it is an incorrect answer.