question_answer

Classification of sponges is primarily based on the:

A)  body organisation

B)  body plan

C)  skeleton

D)  canal system

Correct Answer: C

Solution :

 Sponges (phylum-Porifera) are all aquatic having cellular level of body organization. There is some physiological division of labour accompanied with structural differentiation amongest body wall. Sponge architecture is  constructed arround a system of water canals establishing canal system. Outside water is continuously drawn into the canal system through numerous dermal pores or ostia of body wall and collects into the main body cavity (spongocoel) then escape out through a single large exhalent opening called the osculum. Sponges are classified on the basis of skeleton