Explanation:
A
Coelenterates have nematocyst Nematocysts are stinging cell. Nematocysts are mainly concerned with food capture, defense and attachment.
They have the special types of cells called nematocysts, are present in coelenterata only. These cells are used for food catching defensive and offensive purposes.
- Coelenterates are acoelomate. They have a single opening which acts as mouth and anus.
(b) Polymorphism is the ability of an object to take on many forms.
(c) A flame cell is specialized excretory cell found in the simplest freshwater invertebrates, including flatworms, rotifers and nemerteans. Flame cell functions like a kidney, removing waste materials.
(d) Choanocytes, are grouped within chambers. They are the main 'pumping station' for sponge survival.
