Work Step by Step
Option A is incorrect. Implantation occurs when the blastocyst becomes embedded in the uterine wall. Option B is incorrect. Gastrulation is the process by which the three cell layers of the body are formed. Option D is incorrect. Fertilization is the union of egg and sperm cells to produce a single cell. Option C is correct. Neural folds come together to form a neural tube during the process of neurulation.