A) Spiral cleavage, blastopore becoming anus
B) Spiral cleavage, blastopore becoming mouth
C) Radial cleavage, blastopore becoming anus
D) Radial cleavage, blastopore becoming mouth
Correct Answer: C
Solution :
Deuterostomes litearally meaning second mouth are animals in which the mouth arise not form the blastopore but secondarly at the opposite end of the gut (the blastopore it self become the anus). Additionally embiyonic development of deuterostomes includes radial cleavage, an eriLerocoelom and a calcified skeleton when present derived generally from mesodermal tissues. Protosromes literally meaning first mouth are animals in which the mouth arises from or near the blastopore. Additionally tend to have spiral cleavage a schizocoelom and a skeleton derived from the surface layer of cells. Embryonic charateristics modern molecular phylogenes and the fossil record all imply that there was an ancient and fundamental divergence between the protostomes and deuterostomes.
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