• All human cells are derived from a cell created by the fusion of an egg and a sperm nucleus in fertilisation.
• Cells formed in the initial stage of a fertilised egg are totipotent stem cells.
• The cells differentiate from similar stem cells into different tissues and organs.
• Tissue cells are similar.
• Stem cell differentiation is a complex process driven by genes.
• Nowadays, stem cells can be cultured and developed into the desired cells.
• Keywords: cell, tissue, organ, body, stem cell, differentiation, nerve tissue, muscle tissue, connective tissue, epithelial or surface tissue.