Question

Body structure of different animals is given below. Identify to which phylum the animal belongs
1) Long, cylindrical, metamerically segmented
2) Triploblastic , bilaterally symmetrical, eucoelomate
3) They have setae or parapodia or suckers for locomotion

A) Arthropoda
B) Annelida
C) Aschelminthes
D) Mollusca

Answer 1

Hint:Arthropods belong to the phylum Euarthropoda which includes insects, arachnids, crustaceans. The annelida is a group referred to as segmented worms. Aschelminthes is referred to as a phylum of worms like invertebrates. Mollusca is the second largest phylum of invertebrate animals after the arthropoda.

Complete Answer:
The arthropod is an animal which has an exoskeleton. The arthropoda, annelida has a segmented body. The arthropod has paired jointed appendages. Arthropods, annelids are bilaterally symmetrical. Arthropod’s primary internal cavity is a haemocoel which has its internal organs. Arthropods are Coelomate organisms. The arthropods are characterized by their jointed limbs and cuticle made of chitin.
Locomotory organs in arthropods are setae which project through their cuticles. Arthropods and Annelids are metamerically segmented. Arthropods and annelids both are triploblastic. Appendages of Arthropods help in locomotion. So the arthropods are defined as triploblastic, bilaterally symmetrical, metamerically segmented, eucoelomate . The body is elongated. Locomotory organs are seated embedded in the skin.

So the correct answer is Arthropoda. Insects are the largest group of the arthropods.

Note:Mollusca are bilaterally symmetrical but symmetry is lost in some forms. They are unsegmented. Aschelminthes are pseudocoelomate, unsegmented, bilaterally symmetrical and triploblastic. The arthropods use feather-like seats to increase the surface area of swimming appendages. Arthropods have an open circulatory system while annelids have a closed circulatory system. Arthropods are of ecological importance because of their diversity.