Chapter 25, Problem 14A

Summary Introduction

Introduction :

The round worms are called so because their body is cylindrical and long. They are bilaterally symmetrical. The ends of the worms are tapered or pointy at both ends. They are intestinal parasites and they are not involved in active movements. So, their body lack segmentation.

Answer to Problem 14A

Correct answer :

Option (A).

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) Pseudocoelom. The given picture represents the cross section of the round worm, in which a hollow cavity can be seen. This cavity lacks peritoneal lining, which means it is not a true coelom, so, it is a pseudocoelom. Hence, the correct answer is option (A).

Explanation for incorrect answer :

Option (B) Scolex. The scolex is the mouth part of the worms, which is not shown in the picture. Hence, it is an incorrect answer.

Option (C) circulatory system. The given diagram shows gut and body lining only. Hence, it is an incorrect answer.

Option (D) nervous system. The given diagram shows gut and body lining only. Hence, it is an incorrect answer.