Biology · Developmental Biology

Given below are some statements in connection with neural tube formation in vertebrates: A. In primary neurulation, the cells surrounding the neural plate direct the neural plate cells to proliferate, invaginate, and separate from the surface ectoderm to form an underlying hollow tube. B. In secondary neurulation, the neural tube arises from the aggregation of mesenchyme cells into a solid cord that subsequently forms cavities to create a hollow tube. C. In birds, primary neurulation generates the neural tube from the anterior up to the hindlimb developing region. D. In mammals, secondary neurulation begins at the level of sacral vertebrae. E. Anencephaly results when a failure to close the neural tube occurs, resulting in the forebrain remaining in contact with amniotic fluid. Which one of the following options gives all correct statements?