BIO 351 - EXAM 2 STUDY GUIDE QUESTIONS
WITH CORRECT ANSWERS 2026/2027
What is gastrulation? - CORRECT ANSWER -formation of the three germ layers: ectodermal,
mesoderm, and endoderm
What is neurulation? - CORRECT ANSWER -formation of the neural plate and neural tube.
What germ layer is the neural plate and neural tube derived from? - CORRECT ANSWER -
ectoderm
What are the steps of neural plate folding? - CORRECT ANSWER -1. Elongation - The nervous
system starts out as a flat neural plate that runs along the midline from rostral to caudal.
2. Folding - The medial hinge point (MPH) anchor to the notochord and change shape so that
the epidermal cells move toward the dorsal midline.
3. Elevation of the neural folds - The epidermal continue to push and elevate neural folds
4. Convergence - Cells at the dorsolateral hinge point (DHLP) push toward center to bring the
neural fold into contact.
5. Closure - The neural folds fuse at the dorsal midline and separate from the overlying
epidermis. The middle of the neural tube fuses before the rostral and caudal ends
What process makes the peripheral and central nervous system? What germ layer is it derived
from - CORRECT ANSWER -neurulation; ectoderm
What are neural tube closure defects (NTDs)? - CORRECT ANSWER -An abnormality or
disruption in the timing and localization of the neural tube closure leading to various disorders.
Example: anencephaly, myelomeningocele, and spina bifida
WITH CORRECT ANSWERS 2026/2027
What is gastrulation? - CORRECT ANSWER -formation of the three germ layers: ectodermal,
mesoderm, and endoderm
What is neurulation? - CORRECT ANSWER -formation of the neural plate and neural tube.
What germ layer is the neural plate and neural tube derived from? - CORRECT ANSWER -
ectoderm
What are the steps of neural plate folding? - CORRECT ANSWER -1. Elongation - The nervous
system starts out as a flat neural plate that runs along the midline from rostral to caudal.
2. Folding - The medial hinge point (MPH) anchor to the notochord and change shape so that
the epidermal cells move toward the dorsal midline.
3. Elevation of the neural folds - The epidermal continue to push and elevate neural folds
4. Convergence - Cells at the dorsolateral hinge point (DHLP) push toward center to bring the
neural fold into contact.
5. Closure - The neural folds fuse at the dorsal midline and separate from the overlying
epidermis. The middle of the neural tube fuses before the rostral and caudal ends
What process makes the peripheral and central nervous system? What germ layer is it derived
from - CORRECT ANSWER -neurulation; ectoderm
What are neural tube closure defects (NTDs)? - CORRECT ANSWER -An abnormality or
disruption in the timing and localization of the neural tube closure leading to various disorders.
Example: anencephaly, myelomeningocele, and spina bifida
