How does one cell grow into a baby?

One cell, the fertilized egg or zygote, undergoes a series of divisions called mitosis, where it splits into two cells, then four, and continues to multiply. As these cells divide, they also differentiate into various types of cells that form tissues and organs, a process guided by genetic instructions and environmental factors. This complex development continues through stages such as embryo and fetus, eventually resulting in a fully developed baby ready for birth. Throughout this process, the cells communicate and coordinate their activities to ensure proper growth and development.