NTA Abhyas NEET2020BotanyAnimal KingdomPractice
During the metagenesis of Obelia ,
Options
- Apolyps produce medusae asexually and medusae form the polyps sexually.
- Bpolyps produce medusae sexually and medusae form the polyps asexually.
- Cboth polyps and medusae are produced sexually by each other.
- Dboth polyps and medusae are produced asexually by each other.
Correct answer
A. polyps produce medusae asexually and medusae form the polyps sexually.
Step-by-step solution
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. Those 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 ).