This page describes the process of a fertilized egg developing into a newborn through about 41 rounds of mitosis, leading to over 100 diverse cell types categorized into four main tissue types: epithe...This page describes the process of a fertilized egg developing into a newborn through about 41 rounds of mitosis, leading to over 100 diverse cell types categorized into four main tissue types: epithelial, muscle, connective, and nervous. Epithelial tissues protect surfaces, muscle tissues enable movement, connective tissues offer support, and nervous tissues facilitate communication, each with distinct functions and structures.