Question

Which one of the following statements about all the four of Spongilla, leech, dolphin and penguin is correct?

• A. All are bilaterally symmetrical.
• B. Penguin is homeothermic while the remaining three are poikilothermic.
• C. Leech is a fresh water form while all other are marine.
• D. Spongilla has special collared cells called choanocytes, not found in the remaining three.

Answer 1

The correct option is D Spongilla has special collared cells called choanocytes, not found in the remaining three.

The body of a sponge is cylindrical, asymmetrical or has radial symmetry whereas leech, dolphin and penguin have bilateral symmetry.
Dolphin is homeothermic.
Sponges are aquatic animals. They can be marine or fresh water.
Sponges possess choanocytes or flagellated cells and helps in ingestion of food particles.
Thus, the correct answer is option D.