Question

What is the first obvious sign that the nervous system is forming in the embryo?

1) Thickening of the surface ectoderm to form the neural plate
2) Formation of the neural tube
3) Differentiation of neural stem cells
4) Development of the brain and spinal cord

Answer 1

The first obvious sign that the nervous system is forming in the embryo is the thickening of the surface ectoderm to form the neural plate. This occurs during the process of neurulation, which takes place in weeks three and four after fertilization.

Step-by-step explanation:

The first obvious sign that the nervous system is forming in the embryo is the thickening of the surface ectoderm to form the neural plate. This occurs during the process of neurulation, which takes place in weeks three and four after fertilization. The neural plate then begins to fold inward, eventually forming the neural tube, which will develop into the brain and spinal cord.