Which process makes it possible for the major organs of the body to be formed by week 10 of human development

The process that makes it possible for major organs of the body to be formed by 10th week of human development is differentiation.  

Explanation:

Human development is started off by the process of fertilization in which the sperm and ovum fuse to form zygote. In human beings fertilization takes place in the oviduct of the female. The zygote that is formed undergoes mitosis to form the embryo.  

The embryo then gets embedded in the uterine walls. It continues dividing and differentiating  into several organs. Almost all of the organs are formed by tenth week of pregnancy even though they aren’t fully developed.  

The embryo has three layers namely ectoderm, mesoderm and endoderm. Ectoderm develops into outermost skin layer, central and peripheral nervous system, eyes and inner ears. Baby’s heart and circulatory system is formed from the mesoderm and the baby’s lungs and intestine develop from the innermost layer called endoderm.