[Campbell Biology P.723] During gastrulation in most animals, what is the primary fate of th... | Practice Question

During gastrulation in most animals, what is the primary fate of the pouch formed by the inward folding of the embryo?

  • A: It becomes the blastocoel, a hollow cavity filled with cells.
  • B: It develops into the mesoderm, the middle embryonic tissue layer.
  • C: It forms the archenteron, which will develop into the tissue lining the animal's digestive tract.
  • D: It closes completely, forming a solid ball of undifferentiated cells.

Explanation

Gastrulation involves the inward folding of the embryo to form a pouch called the archenteron. This archenteron, particularly its endodermal lining, eventually develops into the animal's digestive tract. The blastocoel is the cavity of the blastula, which becomes filled during gastrulation, not formed by the pouch. The mesoderm is another germ layer, but its formation is not directly described as the primary fate of this specific pouch in the provided text. The pouch does not close completely; it opens to the outside via the blastopore.