Which one of the following phyla is correctly matched with its two general characteristics? (a) Echinodermata pentamerous radial symmetry and mostly internal fertilization (b) Mollusca normally oviparous and develop ment through a trochophore or veliger larva (c) Arthropoda body divided into head, thorax and abdomen and respiration by tracheae (d) Chordata notochord at some stage and separate anal and urinary openings to the outside.
Option C Arthropods are the largest phylum of Kingdom Animalia that characteristically possesses an outer body layer – the cuticle. The body is composed of segments usually forming distinct specialized body regions, i.e., head, thorax and abdomen. In them the trachea or windpipe or book lungs are the respiratory organs found in terrestrial forms, which help in respiration.
