Question

multiple choice question
in bilaterally symmetrical animals, the mouth forms first in animals with _ embryonic development, and the anus forms first in animals with _ embryonic
development
o chelicerate, mandibulate
o deuterostome; protostome
o mandibulate; chelicerate
o protostome, deuterostome

Explanation:

• Protostome: In protostome development, the blastopore (the opening of the archenteron) develops into the mouth first.
• Deuterostome: In deuterostome development, the blastopore develops into the anus first.
• Chelcerate and Mandibulate: These terms are related to the type of mouthparts in arthropods (e.g., chelicerates have chelicerae as mouthparts, mandibulates have mandibles as mouthparts) and are not related to the order of mouth - anus formation in embryonic development.

Answer:

protostome, deuterostome