Rotifera embryonic development is categorized as which type?

• A. Protostome
• B. Deuterostome
• C. Eutely
• D. Spiral cleavage

Answer: (A)

Protostome development means the mouth forms from the blastopore and early embryonic cells have determinate fates. Rotifers follow this pattern: the initial opening becomes the mouth, and early cell divisions set aside specific fates rather than allowing flexible reorganization. This contrasts with deuterostome development, where the blastopore becomes the anus first and cleavage is typically radial and indeterminate. Eutely describes a fixed adult cell number and doesn’t define how the embryo develops. So the embryonic pattern of Rotifera aligns with protostome development.