Question

Which one of the following group of animals is bilaterally symmetrical and triploblastic?

• A. Ctenophores
• B. Sponges
• C. Coelenterates
• D. Aschelminthes

Answer 1

Answer: (D)

Aschelminthes

Animal are classified on the basis of symmetry of body plan and germ layers if the body plan is made up of three germ layers called as triploblastic and if it made up of two germ layers called as diploblastic. Ctenophores are biradially symmetrical and diploblastic, whereas some species are triploblastic.

Sponges are asymmetrical and and diploblastic.

Coelenterates are radially symmetrical and diploblastic.

Aschelminthes are bilaterally symmetrical and triploblastic. Thus, the correct answer is option D.