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Multiple Choice
Which of the following best distinguishes a protostome from a deuterostome during embryonic development?
A
Protostomes lack a coelom, while deuterostomes possess a coelom.
B
Protostomes have radial cleavage, while deuterostomes have spiral cleavage.
C
In protostomes, the blastopore becomes the mouth, whereas in deuterostomes, it becomes the anus.
D
Protostomes develop a notochord, while deuterostomes do not.
Verified step by step guidance
1
Understand the key terms: Protostomes and deuterostomes are two major groups of animals classified based on their embryonic development patterns.
Focus on the blastopore: The blastopore is the opening that forms during the early stages of embryonic development. In protostomes, the blastopore develops into the mouth, whereas in deuterostomes, it develops into the anus.
Clarify cleavage patterns: Protostomes typically exhibit spiral cleavage during early cell division, while deuterostomes exhibit radial cleavage. This is another distinguishing feature.
Address the coelom misconception: Both protostomes and deuterostomes can possess a coelom (a body cavity), so this is not a distinguishing factor.
Eliminate incorrect options: Protostomes do not develop a notochord; this structure is characteristic of chordates, which are a subgroup of deuterostomes. Therefore, the correct distinguishing feature is the fate of the blastopore.