Question

Read the following statements.

(a) Metagenesis is observed in helminths.

(b) Echinoderms are triploblastic and coelomate animals.

(c) Roundworms have an organ-system level of body organization.

(d) Comb plates present in ctenophores help in digestion.

(e) Water vascular system is characteristic of echinoderms.

Choose the correct answer from the options given below:

• A. (b), (c) and (e) are correct
• B. (c), (d) and (e) are correct
• C. (a), (b) and (c) are correct
• D. (a), (d) and (e) are correct

Answer 1

The correct option is A (b), (c) and (e) are correct

Some coelenterates exhibit alternation of generation or metagenesis between asexual (polyp) and sexual (medusa) forms. Metagenesis is not observed in helminths.

Hence statement a is incorrect.

The echinoderms have three primary germ layers during development and hence are triploblastic. Echinoderms are coelomates as the cavity between the body wall and alimentary canal is lined by mesoderm. The most distinctive feature of echinoderms is the presence of a water vascular system that helps in locomotion, respiration and capture of food.

Hence, statements b and e are correct.

Roundworms belong to the phylum Aschelminthes and they exhibit an organ-system level of organization.

Hence, statement c is correct.

Comb plates are a characteristic feature of ctenophores. They help in locomotion.

Hence, statement d is incorrect.