Question

6. If gastrulation did not occur,

A. cleavage would not occur in the zygote

B. the embryonic germ layers would not form

C. fertilization would be blocked

D. the blastula would not be formed

E. B and D would not occur

Answer 1

B. the embryonic germ layers would not form

Gastrulation is a step in embryonic development where three germ layers are formed. The three germ layers are ectoderm, mesoderm and endoderm. The word gastrulation literally means 'gut formation'. From ectoderm the epidermis and nervous system is formed. Mesoderm forms into connective tissues like muscles and bones. Endoderm forms the lining of digestive and respiratory system and also gives rise to liver and pancreas