Question

Which of the following statement/s regarding coelenterates is/are WRONG?
(i) Cnidocytes are present on the tentacles and on the body.
(ii) Diploblastic with the cellular level of organization.
(iii) Polyp forms are free-swimming.
(iv) Many exhibits metagenesis.
(v) Polyps produce medusa sexually and medusa produce polyps asexually.

• A. (ii) and (iv) only
• B. (iii) and (v) only
• C. (ii), (iii) and (v)
• D. (i), (ii) and (iii)

Answer 1

Answer: (C)

Phylum coelenterates are also known as cnidarians as they possess cnidocytes. These are stinging cells present on tentacles and throughout the body. This phylum shows tissue level of organization and is diploblastic as mesoderm is absent. Some organisms show metagenesis. These show two forms i.e. polyp and medusa. Polyp is cylindrical in shape while medusa are umbrella-shaped. Polyp is sessile while medusa are free living. Polyp produces medusa asexually while medusa forms polyp sexually. This is alternation of generation.