Q. Which one of the following statements about all the four of Spongilla, leech, dolphin and penguin is correct?
A) Penguin is homeothermic, while the remaining three are poikilothermic
B) Leech is a fresh water form, while all others are marine
C) Spongilla has special collar cells called choanocytes, which are not found in the remaining three
D) All are bilaterally symmetrical animals
Explanation
Spongilla belongs to phylum-Porfera, in which, choanocytes are the characteristic cells, these are absent in leech, dolphin and penguin.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.