During which process does the amnion envelop the embryo?

• A. Neurulation
• B. Embryonic folding
• C. Fertilization
• D. Gastrulation

Answer: (B)

Verified step by step guidance

1. Understand the role of the amnion: The amnion is a thin, protective membrane that forms during early embryonic development and eventually surrounds the embryo, creating the amniotic sac filled with amniotic fluid.
2. Review the process of embryonic folding: Embryonic folding is a critical stage in development where the flat embryonic disc transforms into a three-dimensional structure. This folding helps position the amnion around the embryo.
3. Compare embryonic folding with other processes: Neurulation involves the formation of the neural tube, gastrulation is the process where the three germ layers form, and fertilization is the union of sperm and egg. None of these directly involve the amnion enveloping the embryo.
4. Identify the correct process: During embryonic folding, the amnion expands and begins to envelop the embryo, ensuring protection and creating the environment necessary for further development.
5. Conclude that embryonic folding is the process during which the amnion envelops the embryo, as it is directly responsible for the structural changes that position the amnion around the developing embryo.