What is actually changing during this process of differentiation?

分化的过程中,实际发生了哪些变化

耶鲁公开课 - 生物医学工程探索课程节选

This process of cell proliferation or cell division is, of course, very important during development of an embryo.

细胞增殖和分裂的过程,在胚胎发育中至关重要

耶鲁公开课 - 生物医学工程探索课程节选