Because a damaged meristem cannot be regenerated, for protection the meristem also produces cells ahead of itself forming a root cap. Root cap cells are readily rubbed off but are quickly replaced from within, much like our skin when it dries and peels from the surface. When root cap cells are ruptured by sharp soil particles, their protoplasm forms a slimy coat lubricating the root tip as it works its way through the soil and around large objects.
