Which of the following is present at the beginning of 3rd week?
Primitive streak appears at the end of the 2nd week of intrauterine life and beginning of 3rd week, epiblast cells in the primitive streak forms the notochord, mesoderm and neural crest cells later in the third week. Disc with three germ layers are formed at 3rd week of gestation. Ref: Gray's 39e/p-210-220
Notochord
Primitive streak
Mesoderm
Neural crest cells
General anatomy