Which statement about animal development is true?
A) Differentiation of cells into different cell types involves signaling molecules.
B) In frog embryos, β-catenin is necessary but not sufficient for the formation of the primary embryonic organizer.
C) Blastomeres are early embryonic cells that form during gastrulation.
D) The mouth of the sea urchin forms from the blastopore.
E) Cells migrate during the blastula stage.

Question

Quizplus · Accepted Answer

Differentiation of cells into different cell types involves signaling molecules. This is because during animal development, cells need to communicate with one another using signaling molecules to adopt specific fates and differentiate into different cell types.

Answer: B
 In frog embryos, β-catenin is necessary but not sufficient for the formation of the primary embryonic organizer. This is because while β-catenin is required for the formation of the primary embryonic organizer in frog embryos, other factors are also needed to complete the process.

Answer: D
 The mouth of the sea urchin forms from the blastopore. This is because during the gastrula stage of development in sea urchins, the blastopore becomes the anus and the mouth forms on the opposite side of the embryo.

Answer: E
 Cells migrate during the blastula stage. This is because during the blastula stage of animal development, cells actively migrate to reposition themselves and form the three germ layers that give rise to all the tissues and organs in the body.

Which Statement About Animal Development Is True