Question

Metagenesis is found in

• A. Hydra
• B. Obelia
• C. Aurelia
• D. Tubipora

Answer 1

The correct option is B Obelia

Life History of Obelia includes both asexual and sexual generations that alternate with each other to complete the life cycle. The sedentary hydroid colony alternates with the pelagic medusa phase. Hydroid colony reproduces by asexual budding to produce hydranths and blastostyles. Medusae are also produced by budding from blastostyle but they are free swimming sexual forms that carry ova and sperms in four gonads and disperse them in water far and wide. Such alternation of generation in which the asexual polypoid generation appears to alternate regularly with the sexual medusoid generation but both forms are diploid, is called Metagenesis. In true alternation ofgeneration one of the stages in life cycle is haploid, whereas in metagenesis both stages are diploid.

So, the correct answer is 'Obelia'.