Question

question 1
katie is in her 6th week of pregnancy. she has been researching the timeline of prenatal development. she knows that at this point the embryonic disk has formed layers. she reads that the digestive system is beginning to develop on the
a endoderm
b ectoderm
c lanugo
d mesoderm

Explanation:

During embryonic development, the endoderm (innermost germ layer) gives rise to the digestive system. Ectoderm forms skin/nervous system, mesoderm forms muscles/bones, and lanugo is fetal hair (not a germ layer).

Answer:

A. endoderm