Question

A bilaterally symmetrical deuterostorne is classified in the phylum

• A. Annelida
• B. Chordata
• C. Arthropoda
• D. Echinodermata.

Answer 1

The Correct Option is B

Deuterostomes are coelomate animals whose embryogenesis includes the blastopore developing into the anus of the animals. Members of the Phylum Chordata are bilaterally symmetrical deuterostomic coelomates.

Answer 2

Explanation: 

MEANING OF TERMS IN THE QUESTION: 

• Bilateral symmetry: If an organism possesses an axis such that the body can be divided into two equal parts and a mirror image is seen in both halves, then the organism is said to have bilateral symmetry.
• Deuterostomes: A major group of animals in which the anus forms before the mouth during embryonic development. This group includes vertebrates, sea stars, sea urchins, and others.

Phylum characteristics of the given options:

• Annelida: segmented worms (like earthworms). Bilaterally symmetrical, and protostomes (mouth forms first).
• Chordata includes vertebrates as well as some marine invertebrates, like sea squirts. Bilaterally symmetrical and deuterostomes.
• Arthropoda: insects, spiders, crustaceans. Bilaterally symmetrical, but protostomes.
• Echinodermata: Sea stars, sea urchins, sand dollars, etc. Adults display radial symmetry, whereas larvae demonstrate bilateral symmetry. They are classified as deuterostomes.

Hence, Chordata is the correct answer.