Specialised cells, unspecialised cells and differentiation

Most cells in multicellular organisms are specialised – they have structures that are adapted for the jobs the cells. Multicellular organisms grow (make new cells by mitosis) and develop (make specialised cells to form tissues/organs). Unspecialised cells become specialised through a process called differentiation. During differentiation, particular genes in the cell’s genome are switched off or on. Specialised cells only use particular genes, so only make the proteins needed for the job they are adapted to do.