Age of child ???
Info presented to kids needs to fit their abilities to understand ideas.
In young kids-simple & short "planted 3 & only one is growing" will do. They often come back later with short ?S and again short answers work best. After 7-8 a basic explanation may be helpful. Teens often get caught up on specifics & may grasp the significance. Discussing this with your dr or the kids dr can help guide you.