Soon after the coelom begins to form, a researcher injects a dye into the coelom of a deuterostome embryo. Initially, the dye should be able to flow directly into the ________.
A) blastopore
B) blastocoel
C) archenteron
D) pseudocoelom

Question

Quizplus · Accepted Answer

The archenteron is the embryonic gut that forms during gastrulation in deuterostome embryos. The coelom initially forms as outpocketings of the archenteron. Therefore, if dye is injected into the early coelom of a deuterostome embryo, it should be able to flow directly into the archenteron. The blastopore is the opening that forms during gastrulation, but it does not directly connect to the coelom. The blastocoel is the fluid-filled cavity that forms in the blastula stage, before gastrulation. The pseudocoelom is a body cavity that forms in some animal groups, such as roundworms, but it is not a feature of deuterostomes.

Soon After the Coelom Begins to Form, a Researcher Injects