Phylum Ctenophora MCQ - Practice Questions with Answers

• It is a small phylum with 90 known species. The animals of this phylum are commonly called comb-jellies or sea-walnuts. 
• These are exclusively marine, radially symmetrical and diploblastic animals.
• They bear eight external rows of ciliated comb plates, due to which they are named ctenophores; ktene - comb, phoros - bearing.
• They show tissue level of body organization
• Examples : Pleurobrachia and Ctenoplana

Locomotion in Ctenophora:

• The ciliated comb plates are responsible for locomotion. The cilia beat in a coordinated fashion making the animal to propel in a particular direction.

Bioluminescence in Ctenophora:

• Ctenophores have an ability to give off light called bioluminescence. It occurs in special cells called photocytes that are present below the comb-plates
• Colloblasts are adhesive cells found in Phylum Ctenophora 

• Ctenophores reproduce only through sexual means. Fertilization is external and the development occurs through larval stage, hence it is indirect. 

Statocyst:

• Statocyst is the main component of the sensory organ present at the opposite end of the mouth. It senses balance.