It's not like your heart cells and kidney cells get all mixed up every day, and that's because there's all of this chemistry going on, these molecules that say who each of these groups of cells is and what their tasks should be.
Nije kao kad se stanice vašega srca ili bubrega pomiješaju svakodnevno, a to je zato što se sva ta kemija odvija, ove molekule govore koja je koja od ovih skupina stanica, i koja bi im trebala biti zadaća.