Q. Which of the following scales are similar to mammalian teeth?
A) Cycloid
B) Placoid
C) Ganoid
D) Cninoid
Explanation
Placoid scales are similar to mammalian teeth. It is characteristic feature of elasmobranch fishes only, each placoid scale consists of a backwardly directed spine arising from a rounded basal plate embedded in dermis.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.