Question

Which one of the following is not a characteristic feature of sponges?

• A. Cellular level of organization
• B. Presence of ostia
• C. Intracellular digestion
• D. Body supported by chitin
• E. Indirect development

Answer 1

The correct option is D Body supported by chitin

All sponges are aquatic, mostly marine and are found from the deepest oceans to sub-terrestrial environments.
They are the most primitive of the multicellular animals. Their bodies lack true tissues but are composed of many different cell types, each with special functions.
Some sponges have the ostia. These are inhalant breathing pores, which are clustered on the ends of the blind fistules to prevent smothering from the sediment.
Sponges do not have a proper digestive system or circulatory or nervous system. Intracellular digestion takes place in sponges i.e., digestion occurs within the cell.
Sponges have their own version of indirect development through non-feeding larval stages.
However, the sponge's body is not supported by chitin. The sponge skin is composed of special cells that surround the upper and lower surfaces of the body with a middle layer in which all the other cells occur.

Thus, the correct answer is option D.