Question

Identify the phylum X.

• A. Porifera
• B. Aschelminthes
• C. Platyhelminthes
• D. Ctenophora

Answer 1

The correct option is D Ctenophora

Ctenophores have tissue grade level of organisation but are radially symmetrical. They are diploblastic and have no body cavity or coelom. Hence, they are called acoelomate.

Poriferans show a cellular level of body organisation.
Organisms in phylum Platyhelminthes and onwards are bilaterally symmetrical.
Platyhelminthes show organ level and Aschelminthes show organ system level of organisation, i.e., organs get associated to perform specific physiological functions.