By the third week after conception a sheet of primitive neural cells forms a:
A)hollow tube called the neural tube.
B)cavity called the ventricle.
C)hollow tube called the stem cell.
D)cavity called the amniotic sac.

Question

Quizplus · Accepted Answer

By the third week after conception, the sheet of primitive neural cells folds inward to form a hollow tube called the neural tube, which eventually forms the brain and spinal cord. The other options - cavity called the ventricle, hollow tube called the stem cell, and cavity called the amniotic sac - are not accurate descriptions of early neural development.

By the Third Week After Conception a Sheet of Primitive