Q. Metameric segmentation (metamerism) is first observed in which of the following phyla?
A) Platyhelminthes
B) Aschelminthes
C) Annelida
D) Mollusca
Explanation
Annelids such as the earthworm show external and internal segmentation with serial repetition of organs. Platyhelminthes and Aschelminthes are unsegmented, and molluscs are unsegmented.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.