Question

Q?: The zooid nutrition is sedentary and the zooid reproduction is free swarming, these both contribute in which phylum?
(A) Annelida→Segmented-worms
(B) Arthropoda→Animals with jointed-legs
(C) Cnidaria→Stinging celled organisms
(D) Echinodermata→Animals with spiny-skinned
(E) Platyhelminthes→Flatworms​

Answer 1

Answer:

Hydrozoa Cnidarians exhibit two basic body forms called polyp and medusa. The former is a sessile and cylindrical form like Hydra, Adamsia, etc. whereas, the latter is umbrella-shaped and free-swimming like Aurelia or jellyfish. These Cnidarians, which exist in both forms exhibit alternation of generation (Metagenesis), i.e., polyps produce medusae asexually and medusae form the polyps sexually (e.g., Obelia).